If you can stretch the funds a bit futher you might even consider an
ATiK 16IC. If we ever get any fine weather up here I'll even try it out.
Here's one of the US stores for comparison price
http://www.astrovid.com/prod_details.php?pid=3246
I've used the original DSI for autoguiding with K3CCDtools V3 and it did the job. I use a guidescope though.