Yeah we at are looking at 2 more months or more of full out winter here. But I have the reg cab in my truck. Is that going to limit my sub capability.

 

Having a regular cab will limit the sizes you will be able to run unless you do some cutting from the cab to the bed, some do that, I don't recommend it. You should easily be able to run dual subs in a good box, 2 amps and however many speakers you are willing to work with.

Also since you have a regular cab I would definitely recommend a component set in order to maximize the sound quality in small space.

Now, on the subject of round vs oval speakers, the truth is that the more area you have on the speaker the more bass response you will receive but at the risk of losing clear higher frequencies. If you want clear and concise sound then a set of 6.5 Kappa components will kick ***, but you should back it up with a good sub/amp combo. If you want a good thump, good frequency response, and don't want to sacrifice space in your cab then you'd be well off with 6x8's.

Simply put, if you want a concert and are willing to spend money over time then go round. If you want good sound and want to keep it inexpensive then go oval.