Printing can often be done in college, saving oneself the trouble of transporting and voltage-converting a printer. You need to keep in mind that the voltage is different in the UK and US and thus a transformer may be necessary. But this issue can permeate the decision making process. Many IBM compatible PC's do also, but ask the sales and support people about this. For example, it might happen that the computer itself will work fine, but the monitor or printer requires a transformer anyway.
Laptops are the least bother and fairly inexpensive.
You'd only need a transformer for peripherals like a printer or external monitor. Also, since the phones are different, a modem from the states won't work without an adaptor. Buying in the UK eliminates this difficulty. Someone's going to have to contribute some information to this one. And BT , as well as some other outfits, will set you up with a direct connection to the internet.