That's around 900 cubic feet. Hmmm. Well, the
Monoprice 9723 gets my vote. Or if you'd like something a little smaller, the
BIC V1020 or the
BK Electronics Gemini II might be a better choice. In any case, I think the Dayton SUB-1500 would be pretty inconvenient in a room that size.
Are you any good with wood working? I'm wondering if importing a subwoofer driver and amp only while building your own enclosure would give you a better value than importing the much larger and heavier finished product. For example, I've been helping a guy in Japan with a design for a
subwoofer in a concrete form tube that only takes up about a square foot of floor space. Something similar might be worthwhile for you to consider as well. Do you know of any stores in Israel that sell raw drivers, amplifiers, and DIY speaker building components?