Do I need a subwoofer? Which brand and model?


I mainly listen to classical and jazz - mostly trumpets and violins, with the occasional piano, viola or bass guitar. A couple of my friends have been suggesting to me that my ensemble lacks bass and having a subwoofer will address it. My setup includes a 2 ch. NAD C365BEE integrated amp, Wharfdale EVO 50 loudspeakers (pair), and an Oppo BDP 105 Bluray player as a CD player. The setup is in the living room, with three walls, and the fourth side open to the dining room. The living room itself would have been 18' L X 12' W X 18' H = 3888 cu. ft, but the fact that it opens up to the dining room makes the entire space more like 40' L X 18' W X 12' = 8540 cu. ft. Would I benefit from a subwoofer and which one should I get? Budget $1000 or close to that.
shugho
I am seriously considering tape at this point :) (partly joking) I found a recording studio mentioned in that link in my post earlier that will actually make them as custom orders - at $125 each! I wonder if the sound on tape would be better than on CD and what tape players are now available. Interestingly, my NAD player has tape inputs.
Thanks Verneal, for your suggestion. I have moved beyond the subwoofer at this point. I should probably start a new thread.
ordered a few of the CDs mentioned in that earlier post. Will let you guys know if they sound any better on my system than the previous ones I mentioned.
Post removed 
"Good advice Zd. Can you explain what you mean by a reference system?"

Listen to as many systems as you can, and pick one that you could live with for a long time. Then use that system as a template/reference in building yours. Basically, you're setting goals.