Two subs no matter how small can take up a lot of room once you have optimum placement.
My recommendation would be to look hard at Funk Audio. They are in Canada but ship anywhere. Your room is big and they make gorgeous 18" subs that are sealed, compact and have amazing output. One of the finest subs made. If you give Nathan a call, you might find he has what you need for a better than expected price. That's all I can say there.
They make a sub called the 18.0SE - It's a more affordable, but equally well performing version of the 18.0 - basically, it's made less pretty, but performance is identical. I know your budget, so sorry for mentioning it, but that 18.0SE performs in Paradigm sub2 territory. See databass.com. it is a few db's down of the sub2 below 20hz, but at maybe 50hz - 80hz equally then surpasses the sub2 in db's.
They are no joke, all drivers and amps are made in house, and has produced what some consider one of the finest drivers, equal in performance to an LMF 5400 (sorry can't remember the exact name for it) yet it's far lighter.
IMHO if you want to save space, get one really really great sub and be done. They offer staggering performance. Another option would be the 18.0c, less expensive, sexy as hell, and a fabulous performer, half the output of the 18.0 or 18.0SE, but priced right for a two sub setup. Please, understand, half the staggering performance of an 18.0SE is still crushing performance, but a great option two step up your output without killing the bank. Also, they are extremely advanced DSP subs....so tune your heart out. It's been said Nathan can possibly do it over the net for you. You'll have to verify that.
Sorry for the long post. I know I'm pushing budget a bit, but I'd put all the money you have (2k vs 1.5k) into the right "forever" sub(s) and worry about the EQ equipment later. A focus on performance and quality now, buys you plenty of time to EQ it later. Also a more devastating tight punchy musical sub like the 18 SE that has excellent 10hz output up to a distortion free and clean/usable 250hz means you can blend it with flipping bookshelf speakers if you were so inclined.
Bah, sorry for the over pitch, but Funk Audio is something special and worth a look. I hope something I said helped. Best of luck on your search.