Well you have a decent size space especially if you take into account the open space makes it over 5,000^3 ft....
I googled that sub you mentioned (have never heard of Omega speakers before) and the specs do not look that impressive nor do they give you an measurements or response curves. Not to mention the cost of $1,450 (DeepHemp Sub purchased seperately without any other omega speakers) for a sub that has an 8" driver and only a 220 watt amplifier in an 20"h x 14"w x 12"d enclosure that only weighs 50 lbs -- this looks like a completely over priced and uderspec'd sub to me. Love the statement in the 'specs' for frequency response "in room response to 26hz" no +/-3db measurement to be found...
You said you wanted to try something other than HSU or SVS -- but you do realize there is a reason so many have their products?? Because they have measured and documented extremely high performance at exceptional prices...SVS PB12+ (veneers available), HSU ULS-15 (many veneers available)...etc -- these are all less than that $1,450 as well...
Also, if you are seriously looking at speding $1,450 on a sub and don't want SVS/HSU you could get a used JL F110 for less than $1,450 and that would most certainly walk all over that 'hemp' sub....10" JL W7 driver, 900watt amp, absolutely some of the finest craftmanship in the cabinet, and included ARO room eq -- there is one listed on Audiogon right now for $1,250...
In short you have many alternatives that will give you superior performance...