which 12’s should i get?

You really can't miss. If you go the ebay route almost everything will fit your budget. For the heavy low bass most people would suggest a ported enclosure. There are some really good prefab ones out there that fit in the general requirements given by most companies.

Kicker is one off the top of myhead  that gives a lot of different reccomended box suggestions.

You have plenty of power to spare and if space isn't an issue I would suggest looking around at some places and listing to whats available and see what sounds best to you,

I bought and sold a lot of subs, from low, mid, to very hi-end and have not been disappointed yet. The box will make a huge difference, along with the proper setup of the amp.

Not sure about Kickers but Audio Enhancers (AE) makes some nice boxes. Plus they make a lot of sub specific boxes for brands like MMats, JL, Diamond, and Kicker. Built to their specs for airspace and port tuning frequencies. But if you have the time and ability building is a great option

No matter the sub you would be smart to properly set your amps subsonic filter at or above what the box is tuned at. Then set your crossover to your listening preference. This will help keep you from damaging any sub you may decide to purchase.

They are prefab.

But they do make enclosures specific to certain companies and their suggested specs. Add a couple of braces and your ready for action

So have you made any choices on the subs yet?

I hope they sound as good as they look. Hadn't had a chance to try or hear any of the RE's yet.

Post an update after you break them in and let us know how they sound.