DIY ESC with reverse Plan Needed

[wolfsong]

i'm looking for a plan to built my own ESC with slow start and reverse.
i don't need a very fancy one or small in size.. just simple and cheap. i have to built 4 for my boat.. so price is important... got to be 12 volt about 25 amps max ( im running 12 volt blower motors on my shafts).
thanks...

ps.. if anybody builts them and can make 4 let me know

[chipmonk]

you might like to take a look here
http://www.pt-boat.com/electric/speedcontroller.html

[wolfsong]

i actually need 4 seperate independent speed controllers for my boat :-) no combined unit