Ive got a set of 10" subs that run 130w RMS, and a set of 6.5" speakers that run 65w RMS. Can i get one amp to power all 4 speakers, a 4 channel maybe that will not blow the 6.5's but will not under power the 10's?

if you got a good 4 chan amp that can run 2ohm stable you can run the 6.5's on the first two chan and bridge the other two and run the 10's in parallel at 2 ohms and you would be ok with plenty of power

2 amps, each matched to their repsective speaker load.

It would sound much better if you added a second set of 6.5's and use a 4 channel amp such as these

http://www.onlinecarstereo.com/CarAu...x?CategoryID=3

And a mono amp in paralel as mentioned above

http://www.onlinecarstereo.com/CarAu...x?CategoryID=1


these are what I would buy, Pioneer cheap and good enough for a boat and will last and sound decent for the system you are putting together

sub amp

http://www.onlinecarstereo.com/CarAu...roductID=16659

mids / highs amp

http://www.onlinecarstereo.com/CarAu...roductID=16660

ive got a second set of 6.5's, i was going to run them off the deck, the deck is the clarion water proof, CMD5 (something like that)

cleaner power through the amp and for the low cost of those amps it will be well worth it, what kind of 6.5's and subs do you have? where are you putting the subs