2 channel setup - Should I add a center channel or $1500 subwoofer?


Hey everyone I just bought the B&W 702 s2 as a 2-channel start to an eventual home theater, but I only have another $1500 in my budget for right now. Should I add a matching center channel that runs at $1500 or use the money for a decent sub? If so what sub would integrate well with my speakers? Would the SVS SP-4000 be a good choice?
km1181
Do you already get the center image from your 2 speakers? When I sit in the center between my speakers, you would swear that the center speaker is on when it isn't.  In that case I would get a sub. 
Short answer is sub, but depends on where you sit probably. Good luck.
Sub first.  
SVS fine.  
Quantity of subs is more important than brands as far as room modes.
For video, the quality of the center spkrs is extremely important for dialogue. Taj your time to get a good one.
Really depends on your priorities. Is this a home theater under construction or a audio system that you want to enhance over time to also be a home theater. If audio is your priority... a sub. If HT then center channel.

Something like 85% of HT sound comes out of the center channel. So from a HT perspective really important.