Roger,
Here's my opinion.
You can take pictures of deep space objects with shorter exposures than 1 minute - I'm typically using 15 second sub exposures but stacking a lot of them (50). These will not contain the same detail that you get with a longer sub but they will also contain a lot less noise. If you want to see what you can achieve with a DSI II and a 15 sec sub in a 10" scope here is a link to some of my attempts. None of these images are greater than 15 sec subs.
http://www.flickr.com/photos/11730783@N06/
The Meade software is supposed to accomodate a bit of rotation but I have not seen this work so don't know how successful it is. Having a larger aperature scope means you can get away with shorter subs. You can always move to longer guided exposures in the future as I am just about to.
I take my 10" Newt and EQ6 to public outreach events and can set up and pack up on my own in about the same time as the clubs C11 can however the C11 typically needs 2 people. The EQ6 head is about 16 kgs.
I know you don't want to mix/match but if you end up with an EQ style mount this will be hard to avoid. I'd get a HEQ5 pro or an EQ6 pro and a DSI II and try your 6" newt on it first? You won't need a focal reducer with this combo. You can then add a SCT later.
Peter