You'll want one that uses AA batteries probably. For a non-digital SLR your pictures will want some photoshop work just to tone down the Disney colours most consumer digitals produce. Best bet is go for one that does as little in camera processing as possible, so you get a nice dull, soft, flat image that still has all the information to be brought out in photoshop. Think about the Canon A95 maybe, using low sharp setting and set on two stops down all the time (rain or shine).
I got an A80, and it's now replaced my old SLR, gets some great pictures (after photoshop), and the batteries last ages if you use high capacity rechageables, but Duracells last a couple hundred shots as well. Only problem is getting shallow depth of field, but you can't have everything I guess.