Audio Budget - What to get??

[Grant]

You won't want a more powerful sub ginge.

Niall has hit it on the head for you setup there. The amp would happily drie the sub and speakers, but leaves you the versatility to buy another amp for the sub in the future, and amp all speakers in the car.

Don forget in your budget that you will also be needing to buy wood, screws, wiring kits, felt or boot carpet, fibreglass, sandpaper, paint(?) the list goes on...