There are a few different basic styles of tubes. I have fished in both a U-tube, and a pontoon style tube, and I have a couple old donut style tubes too.

Everyone is going to have a different opinion on what you should get, but ultimately it comes down to what is comfortable for you.
My lastest tube is a Caddis NavII, and I like it a lot. Of course, it has it's drawbacks, but ultimatley it is a good tube. Turner's had a sale on them a while back for $99--retail is around $179.

For waders, I would just get the most inexpensive neoprene chest waders you can get. You can get a pair for around $40 at Cabelas or Sport Chalet. If you take care of them, they should last at least a few seasons.