The two most important aspects to consider when selecting a solar path light are: The size of the light - how much area it covers. The brightness of the light - how bright it is. I would recommend that you start by trying a few different lights in your room and see which one gives you the best coverage.
You can always add more lights later if you find that you need more. The next step will be to figure out what kind of fixture you want. There are many different kinds of fixtures available today. Some of them are designed for recessed applications, others for surface mounting. Some are made from glass, some are made from plastic.
Some have a diffuser, some don't. You'll need to decide what you want for your project. I would recommend that you start by thinking about the placement of the light - where it will be mounted - and then think about what kind of fixture you want. In the end, the decision will come down to how much you want to spend on your project. Depending on how large your room is, you can get a solar path light for as little as $20 or as much as several hundred dollars.