Most RME stuff has audio loopback (actually the internal matrix will allow several applications to use the same ASIO Driver).
I have the Raydat myself BUT, it does not have analog inputs.
Check their smaller interfaces, like the fireface 400 or the babyface, and be sure to check if the have routing and multi-client capabilities.
Meanwhile you can check VSTHost (http://www.hermannseib.com/english/vsthost.htm
) since it will "encapsulate" multiple VST's in one only software, and it can record their sound. You can then import that audio into reason again, and apply any processing you wish to the imported tracks. It's not a perfect solution but it will get you going while you don't get a new interface.