You could just measure out your boot, get some half inch ply/MDF and build it yourself A lot of these sorts of installations are either home brewed or done by an ICE shop, which may be expensive..............
If you do cover up the amp, you may need to think about forced cooling, which would entail using fans and a relay
Cant really stealth a sub so much though theres the fact they need a certain amount of airspace my new box im gonna be building is bloody huge but its supposed to give the best SQ.