I agree. I think a week is just fine, and renting for more than a week doesn't make sense if you can buy one for not much more.
I got my wetsuit about a week before my tri, and it was fine. Just practice taking it on and off. Both wet and dry, just to get used to it. Swim in it at least once, maybe twice.
Also, get Body Glide. Put it on your ankles and feet. When you try to remove your wetsuit, it will want to stick to you. This helps you to slide it off. (I had misinterpreted someone, and thought to put it on the wetsuit too, and it was very hard to remove - don't do this! Only put it on your skin.
P.S. - How are the swim workouts going?
6/7/09 Great South Bay Sprint Triathlon (750m, 11mi, 5k), 1:43:45
6/20/09 Diamond Dash for a Cure 5k, 32:45
7/5/09 Independence Triathlon (500m, 8mi, 5k), 1:12:30
11/15/09 Damon Runyon 5k Yankee Stadium, 39:44
| current weight: 192.0