What kind of subs in a 97 ext cab Silverado

Ok, a friend of mine wants to put 2 10" subs in his 97 extended cab Silverado, What kind of subs would work for under the back seat? Also, what kind of amp would be best to power those subs. Remeber, this is a budget install, and he dosen't want the high end stuff. He just wants a little extra bass for his sound system. All the other stereo is factory (including the cd player). And how do you hook up amps to a factory stereo?...Ive never had any experience with stuff this new...All we have is older vehicles.

I was wondering maybe Punch stage 2 or something, I don't want any sony stuff, (course i know that you wont recomend it...but it was what he was thinking of), the last xplod stuff I heard sounded like shit....

Ok you say I budget system but can you be a little more precise. Keeping it cheap I'd look at some profile amps and some re series subs from re. ED's K-series would work well too, but I'm not as big of an ED fan as RE. To hook the amp up u gotta get what's called a line ouput convertor. A lot of profile amps (I know the ca600's did) will actually come with one. It's a simple process you just have to splice into your rear speaker wires and hook them up to one side of the LOC then the other side is RCA's to hook into your amp. As far as remote goes, since you have no remote wire comming off of the factory head unit you'll need to rig up a switch. Do one of two things run a wire from the batt to the remote input on the amp or run a wire from the power input on the amp to near the driver back to the remote input on the amp. then just mount the switch somewhere convinient.

Ok you say I budget system but can you be a little more precise. Keeping it cheap I'd look at some profile amps and some re series subs from re. ED's K-series would work well too, but I'm not as big of an ED fan as RE. To hook the amp up u gotta get what's called a line ouput convertor. A lot of profile amps (I know the ca600's did) will actually come with one. It's a simple process you just have to splice into your rear speaker wires and hook them up to one side of the LOC then the other side is RCA's to hook into your amp. As far as remote goes, since you have no remote wire comming off of the factory head unit you'll need to rig up a switch. Do one of two things run a wire from the batt to the remote input on the amp or run a wire from the power input on the amp to near the driver back to the remote input on the amp. then just mount the switch somewhere convinient.
I did something similar to that only I just cut the RCA hookups off one end of the RCA cable and spliced it into my rear speakers.