Grady since you showed us your clever setup I have been thinking outside the box.
The qsi set up I am interested in is the one with the 8 position filter wheel. They are 31mm filters and can produce vignetting at f-ratios less than f4.
Larger filters will stop vignetting (so I have heard)
So I have been considering mixing and matching my own set up and I have come up with the following:
QHY9
Apogee 9 Position Color Filter Wheel - 50mm Round
http://www.optcorp.com/ai-afw50-9r-9...0mm-round.html
Starlight Xpress Slimline Off Axis Guider
http://www.optcorp.com/starlight-xpr...is-guider.html
Now the question is whether these elements can be combined together and with which adapters?