I think you can connect it to the 1200's IDE port (with the appropriate 44-40pin adapter, of course), but check with Jens Schoenfeld to confirm (might depend on the specific Catweasel version).
As to your clockport expander, I think the Catweasel driver supports connecting to different clockports and the Subway definitely does, so that's a valid option from the software side. If you're concerned about the clockport expander hardware itself, that's a different issue
