Hello pkatsuleas,
I notice you seem to have 2 amp setups, a tube setup with a Jolida tube integrated amp and a solid-state separates setup with a ss Schiit preamp and a ss McCormak .5 amp.
All good stuff but I need a bit more info before I can offer meaningful advice:
1. Do you alternate use between both of these systems?
2. Are they used for music only or do you also use for some form of home theater audio?
3. What's your budget range minimum to maximum?
4. REL are nice subs but there are other high quality subs at more reasonable prices. Are you willing to use other brands of subs?
5. Are your speakers set up along the long 30' wall or the shorter 14' wall?
Thanks,
Tim