This may seem a little odd by conventional thinking but the Oktava MK-012s with Omni capsules make stellar room mics. They have excellent low-end response for a SDC. I just made the switch over to them from ribbons and couldn't be happier. I do prefer cardiod for them in my room, but the omni capsules for stereo room mics worked well too. If you do go the ribbon route a Fet boost like the cloud-lifter might be a good idea as well as you're not going to get much output with ribbons pulled so far back from the source.