Xterra is a good brand that frequently has 50% off sales. They also have a very nice return policy if it doesn't fit you right. You can actually swim in the suit and then return it.

Promotion also makes a good, very reasonably priced suit. Their customer service is excellent. You can call and talk to them about your size, body type, etc. and not get the hard sell.

If you have a big size difference between your top and bottom, DeSoto makes a 2 piece suit. You can mix and match sizes to get the best fit. They do tend to be a bit more expensive.

Like any other clothing, different brands fit very differently. If you have any way to try on suits that would be your best bet.

You don't wear anything on your feet in a race. For training you can put on scuba booties if you need them. There are also neoprene caps that you can get to keep you head warm in cold water.