Re: First System, any advice?
Sounds awesome, really. Yea, get 4V outputs if you can, but I've had solid results with 2V HUs. Those Boston amps get thumbs up from anybody who uses them, and the SPG sub does too. I'm running the brand new GTA-1000m amp for only $239 from Sonicelectronix, and it's LOVELY. (Hifonics price with Boston quality.) I would look into a Kinetik battery if I were you. They outperform the Optimas for a marginal price difference. I plan to go with Second Skin sound deadening products when I get around to it.
Simple SQ System:
Head Unit: Alpine CDA-117
Active Crossover: Cache' CEX
Front Stage Amp: Boston Acoustics GTA-704
Components: Polk Audio DB 6501
Sub Amp: Boston Acoustics GTA-1000m
Sub: JBL P1224, 2.5 ft^3 @ 25 hz enclosure
Rear Fill: Sony Xplod 5.25s on HU power lolz