A couple of thoughts on this since small rooms are tough with subs.
Most importantly, sub placement in a small room is critical. Be careful about putting a sub(s) too close to a corner. Two subs will be better to cancel out the nodes.
The JL audio Fathom subs have a very small footprint and have an excellent built in DSP that will help with nodes/modes
An external DSP to eq the subs may be very handy in the small room since there is so little room and you may have to sit in a null or mode.
Good luck!