Newbie needs advice on amp selection

[Mack454]

I will be taking ownership of my 05 Titan in either August or September and plan on installing a carputer (or truckputer in this case).

I plan on using the stock head unit (6 CD changer) for now, but need some advice on a decent amp to go with using the stock HU and stock speakers. I will probably add maybe 2 10" subs under the rear seat (05 SE KC 4x4).

I have never installed an amp before, so any feedback on whether to go with a 2 or 4 channel would be appreciated. I don't need the loudest system, just something a little more powerful than stock (a friend of mine has a Titan so I can compare sound volume and quality from his).

Thanks.