Different subs in pairs?

Okay - here's a question that I haven't seen addressed elsewhere. I have a medium to largish room with pretty nice in-walls (a remodel removed my listening space and floorstanders). I am using an REL Britannia B3 as a sub, and while it's very musical and integrates well, I've got two problems. One is that I'm picking up fm over their high level connection. I didn't have that problem until I placed the sub in a better spot and had to stretch out the 3 wire hi level connection which made a nice antenna. Secondly, I want to try to address some room nodes and believe that 2 subs instead of 1 might help me balance things out. I don't need more bass, I need more even bass.

I doubt I'll find another B3 - so I am considering REL's new S3 which has wireless built in (the best connection according to the factory) which would help me address problem 1 - the fm bleed through.

My question: Anyone see a big problem in pairing an REL S3 (or S2) hooked up through their wireless system in the left channel and the Brittania B3 hooked up hi level directly in the right channel? Same signal, routed differently. Two subs w/ essentially the same voice. I think. I'm past worrying about imaging as I'm working with in-walls. And, given the input flexibility, I think I can get each sub to work smoothly with it's respective channel.

I know it's an odd idea, but I like the B3. If not, you'll see it for sale here shortly because I have to do something to fix the two problems I'm having.

Another option is just buy a less expensive pair of subs like the Martin Logan Dynamo 1000Ws or 700Ws which have wireless built in.

Any wisdom to share?