Here are some options for you as motorsport has suggested:

http://www.rcslot.com/pc-radio-contr...s/PRB2051.html

http://www3.towerhobbies.com/cgi-bin...?&I=LXRXZ0&P=7

http://www.rcslot.com/pc-radio-contr...s/PRB3751.html

You can set one of these up with your own, quality components to make a fast fun boat. I'm sure that others and myself can suggest running gear if you want to pursue this route.

Or, here are some rtr's that could be considered:

http://www.rcslot.com/pc-radio-contr...s/PRB3750.html

http://www.rcslot.com/pc-radio-contr...s/PRB3100.html

http://www.rcslot.com/pc-radio-contr...s/TRA1502.html