Apologies if this is long winded and plenty fragmented.

I'd advocate spinning rust hhd due to the potential for a non-instant failure mode. S.M.A.R.T. has saved me plenty of times and I transfer 100% data off without loss.
I might also say: NVMEs are super light and good capacity. Easy to use either usbC/B/A depending on what USB cable you have. No externally powered, just on lead powered. They are the fastest to access and are my convenient walk around backup style thing.

For a actual DR style backup - I'd likely still choose spinning HDDs. One or more. The more you don't want to lose it the more copies you have. Then even more concerned - buffered ECC ram for your storage server. Don't want corruption induced loss.

Really depends on what you value and want: For every option I usually go for: bang for buck by the numbers.

I wrote a script that scrapes and calculates the metrics I used to manually perform: $/GB (TB), capacity, price, brand, model, date listed, shop etc from my local stores.
It's easier when you see it all on a spreadsheet and can sort by size, price, bang for buck etc. much easier.

Here, there's also sites like: https://www.staticice.com.au/ - that's for when you know what you want, then you look for the best price supplier.

I'd probably suggest: Seagate Exos or IronWolf Pro but even then mostly I go by the numbers.
What numbers? cost divded by capacity is the lone driver for my choice. Unless there's a reason to not select, like SMR. I don't run a NAS so - SMR probably wouldn't affect my decision.

WD Reds started using Shingled Magnetic Recording (SMR) storage and the NAS users seem real upset - apparently. Who knows when they all will do it, you'd have to look that up - if you care for NAS drives beware. Conventional Magnetic Recording (CMR) drives write data on a hard disk in tracks that do not overlap and I would prefer CMR based on the troubles I've read about but it still might not limit my decision. It'd be nice if the NAS vendors and the HDD vendors got together for a compatibility party to sort out how to exist together instead of the users finding out when they hot swap in.

My DR plan would be after copying the data, uplugged and sitting on a shelf so I would likely buy the largest & cheapest disregarding SMR/CMR.
a usb cradle makes it quick to plug it into for additional backup or recovery and I have one.

My ongoing plan is: upgrade disks before they fail. If the new fails, at least the old data is still ok on a shelf - which leaves me exposed for my own DR plans.
I'm lazy and have cloud backups of things that matter, including photos, the fallout is limited to game files I can get back from steam etc and dash-cam footage mostly.

SDDs have due to there being more memory manufacturers/chip options.

I've had enough times SSDs just exit to feel grateful for S.M.A.R.T. - for a DR/backup solution, I'd choose a spinning disk for that alone.

It still might be overkill for you - it is a circumstantial question. How much space do your photos take? I'd say that would be your bare minimum capacity.

I'd not use smaller but in the past I certainly have: cutting numerous CD & then DVD backups.

There's so much you can do however; what about expose some options you might not have thought about:
- USB memory stick(s) in a safe/desk draw - low $ of entry.
- Spinning rust SATA HDD & USB docking cradle - potentially get a second wind as it dies.
- NVME & USB4|USB3.2 enclosure (and usbc cable) - fast, still a good price w/superior performance

Not product endorsements, I have Silicon Power enclosures and others and they work nicely. I have no idea my SATA cradle but it's generic and functional.
USB SATA cradle example: https://www.amazon.com.au/WAVLINK-Universal-Docking-Function... (example product only)
USB3.2 M.2 NVME enlosure example: https://www.amazon.com.au/Yottamaster-10Gbps-NVMe-Enclosure-... (example product only)

I'm in Australia and live with the "Australia tax" your prices will likely differ. I expect the balance/scales of things might be somewhat the same.

USB flash
https://www.officeworks.com.au/shop/officeworks/p/sandisk-cr...
I did exactly this recently for my partner. Just take a full copy to one (or more). The more redundancy you have the more... redundancy... you have!
80GB (165) / 29 == 2.75862068966 GB per dollar (AUD).

AUD$30 isn't much for a quick and easy throw it in the draw backup solution. Saying that; by comparison:

* Spinning rust 8TB HDD at 26.7559 GB per dollar for AUD$299 - more expensive total, superior capacities, best price per
- also is spinning HDD that might fail gracefully w/S.M.A.R.T.

* 2TB NVME at 12.5786 GB per dollar for AUD$159
- still better bang for buck than USB stick
- can plug it in USB exactly the same but with cable and enclosure.
- fast access, large capacity, physically small.

I would go for a USB4 enclosure for my next NVME simply because my current are all USB3.2
Getting: https://www.amazon.com/Crucial-T700-Gen5-NVMe-heatsink/dp/B0... - a blazing fast PCIe Gen5 SSD in an enclosure is a waste. USB3.2 is not even 10% speed of that. So plug that one into your mobo m.2 slot. I only have PCIe v3 so... buying that right now is a waste for me.

I have 2* Silicon Power SSD PCIe Gen4 w\ 2* silicon power USB3.2 enclosures. One powers a Pi4b 8gb for its mount & main storage.
One is my walk around USB-C memory stick (2 or 4 TB, something outrageous). Like a super size USB Flash stick drive.

Many other drives in my main rig, NVMEs and HDDs and well, I did have a SATA SSD too... not anymore.

Good luck, I hope that helps more than rambles.