What to do first.

[audiobaun 5,000+ posts]

What would you use to run stock splits up front for now and a 300-500 watt sub? No need for crossovers and what nots but as mint as possible.

Id run like an old school US Acoustics 4080 Series II,( ch 1/2 on fronts, and 3/4 bridged @4ohms on like a Kenwood SCV 4 ohm 12 or(Polk) ported @36 htz in 2.0 cu ft..The GTQ 400 will sound great on that set up.Even Cheaper you could find like an Alpine Duo-b 3523-3548-3522 even 3525($30-75) Duo-b and like a 500 mono Alpine amp for like $100 bucks..Maybe a SQubed 10/12 keeping it cheap.Stock speakers never have much of any SQ to them of Stock,within my opinion.