Here's a recommendation from one of BWE member and the price is just right for $99 dollar.
http://m.harborfreight.com/12-volt-1...6pmid%3D124083
If 40psi is not enough amazon has some 100 psi 12v water pump for less than $40. Since the places to launch my kayak usually takes about 1hr to get to the launch area, I figure this will help with my clean up.