its easyer said then done but with a bit off hard work you can wire them up going through the wiring sleeve, unplug the wiring connector block and you should have space to drill a hole in both parts without damaging any pins, its tricky but can be done, as for the amp/amps i have built a false floor, but you could also self tap it to you boot mat (not floor) and it should stay put.
Hope this helps and makes sense :S