I would go with some monitors at least with 8" woofer some Presonus Eris E8 (i have the Sceptres S8 its really one step even higher - price is too though) .
For the sub would recommend at least 10" if really little room and even i prefer minimum 12" that you will put lower but will work better and reproduce better even lower frequencies.
Not sure in there is a Tremblor 12", you can also look at rythmyk audio Subs , i have heard great stuff about them and they aren't that expensive..
Hope this might help,
Elliott S.