For a condo and 2-channel application, I would highly recommend open baffle subwoofers especially if you are fighting room nodes. They are much more neighbor friendly than regular subwoofers as they load the room differently and much more evenly.
Think 1 Eminence Alpha 15a mounted on H-frame per side, right next to your mains but 3 feet from front wall (side wall doesn't matter). The drivers are available from qcomponents.ca at $105 CAD each. Then order a pair of Yung SD200 (not sd200-6) plate amps from partsexpress on sale at $110 USD each and you're all set. SD300 amps would give you a bit more headroom and they are only 10$ more.
Yes I do realize partsexpress is in the States but the amps are amazing value and are perfect for the alphas.
In my condo, I run dual servo-controlled 12'' woofers on each side (OB configuration, H-frame, 4 drivers total) and for music it is miles ahead of the JL Audio Fathom F113 I ocasionnaly use for HT. Listening room has 9-foot ceilings and is about 3000 ft3.
Personally I use a shipping address just accross the border in Vermont and drive down from Montreal every once in a while, but I've ordered from partsexpress directly in the past as well to have audio stuff delivered in Canada and it's always trouble free. There's no way it can cost you over $420CAD for the 2 plate amps.
As a bonus, H-frames are relatively easy to build
What's the rest of your system and what speakers are you using? How big is your room? Average listening levels at main listening position? Type of music?
Another option to power the 8 ohms Alphas on the cheap:
''As a less expensive option to the Dayton APA 150's I also use a 100 watt AV receiver to drive another pair of OB Alphas in another system. Each Alpha employs an 80hz low pass XO from PE. My CD player passes it's digital signal to the AV receiver while it's analog signal goes to a SET which drives the main full rangers.
Since so many folks have upgraded to HDMI receivers there are plenty of good used non-HDMI AV receivers available which have more than enough power to drive the Alphas. The Denon I use cost $35 at a garage sale. An advantage for me in using an AVR is having a remote to control the Alpha's volume.''