Wellcome to the forum, I would suggest that you check www.bassproshop.com and www.cabelas.com type in pontoon boat in the search box and you should see some kick boats in your price range.

Some boats are upgradeable, some have extra accesseries you can buy. Most of the guys on this board think of creative ways to make stuff, using PVC, glue, straps, velcro, zip-tyes, etc. Just takes a little imagination, good luck to you.