I'll have to chime in here and say that car audio gear is a very fanboy oriented topic...everyone loves the brands they buy so watch out...
Now are you going for sound quality or volume? There's companies out there who manufacture pure SQ car speakers...Adire Audio comes to mind, they're probably the company I'm outfitting my next car with. If you want natural sound stay away from subs that POUND because they ruin music. Go with a mildly amped sub setup that's gonna compliment your other speakers, not overpower them. Get a sealed box, bandpasses aren't natural sounding at all...get 10" subs also because they have a faster and cleaner response...however the larger subs will extrend to lower frequencies so if that's what you want test some out at a dealer. Get the pod mountable tweeters that are directed toward the driver, difinately provides more balance of l/r from the driver seat. Clean mounting makes a load of differance so go to a professional.
Now the Dynamat....that is GOOD STUFF. There's plenty of other simliar brands out there that should deliver the same performance: Brown Bread, Beaver Tail....that's all I can remember offhand. Get this done when you're have the rest of the speakers put in. Make sure you go to a professional also, it's not so easy to do this PROPERLY. To achieve the results you're looking for by even mentioning this stuff you're gonna be spending some money...ALOT actually. Every resonant surface of the car should be covered so here's what happens:
Front seats removed, trim panels removed, carpeting removed, dash removed and dissasembled, door panels removed, headliner removed, trunk carpet removed. Floor, trunk, firewall, doors, ceiling all should be covered with the dynamat. The open spaces in the dash that vibrate and rattle should be treated with something, the plexi panel that covers your gauges is the biggest pain in the ass but professionals know what to do. The hard part is putting everything back together properly and refitting the carpeting and headliner so they look natural. That's why you go to a pro shop to have it done, do it in your driveway and it's probably not gonna look so nice. Expect to pay way more than you had in mind to get your car treated. Now if that sounds like a bit too much for your car, just be sure to do the doors, dash and trunk.
Most dealers are comissioned sales so they're gonna rip you off as much as they can, BUY ONLINE! You can save a shit ton of cash buying car audio stuff online as long as you're not trying to find something super dooper rare and expensive. Also be sure to get a Class D amp because the A/B/C amps waste alot of their juice. Geez sorry for running on....