This is the camera I have, and am going to try to use. I still have a lot of work to do to determine linearity, etc etc, but the camera looks promising. Trying to get those darks the other night, I noticed a few things:

1) The Orion filter wheel leaks a small amount of light. It was noticeable on frames > 90s or so, illuminating one side of the chip. A quick google search suggested that the Meade filter slide leaks light as well-- may want to check if this is the case with your DSI.

2) It appeared to have a fair amount of hot pixels as well. Only a few that were bad, but a fair amount that were non-linear, at least with regard to the rest of the chip. Now this was done in my garage in Florida in the summer, so it was easily 90 degrees in there. An unscientific glance suggests that they still leave plenty of room to measure at exposures ~2-3 min, but I need to look at this in detail. That said, it is my intention to do everything I can to keep the star confined to as few pixels as possible over the night, via autoguiding, to minimize noise sources; so hopefully I can just use a portion of the chip without hot pixels. We'll see how I do.

I plan on doing what I can with this camera until I have the money to upgrade. I figure it will take me at least as long to save the money as it will to learn the proper methods, etc, to push my SSII as far as I can take it.

I have no experience with this, but from what I've read, this isn't feasible. The problem is that filter wheels are only accurate to within a few thousands of an inch, which is inaccurate enough to cause milli-mag discrepancies in your flat-fields, due to dust on the filter or whatever. For transit work, you can't vary the optical train without taking new flats. I read that in The Sky is Your Laboratory, which I highly recommend.