hmmmm 900 dollars to spend you can get some brand new shizzz, i bought my 12"xxx for 405 shipped, then since your in the area tommyk can make you a box for about 110-120 depending on what you want, which will leave you about 375 for an amp which i'm sure u can find a nice one to push around 1500 watts for that price, or even a used one.......
I have 2 10in kicker cvr's(dual 4 ohms) w/ a kicker sx600.2. The box i have them in is a custom one for under the back seat of my dodge, so unless you drive a 95-99 dodge ram i cant sell you the box. This system is only a couple months old and in very good shape. The subs hit very sharp and sound great. i was thinking about $650