A good place to begin is an equatorial mount and a decent telephoto. You have a much better chance of achieving pleasing results without too much frustration than you would trying to use a telescope as you're learning, plus the telephoto is good for general photography. Most bang for your limited bucks. My personal opinion is to forget the Astrotrak, your 70-200 will work fine on this mount:http://www.telescope.com/Mounts-Tripods/Equatorial-Mounts-Tripods/Orion-Adventures-in-Astrophotography-Bundle/pc/-1/c/2/sc/34/p/27154.uts
For cameras, a good place to look is astromart.com You will often find modified Canons for sale at a good price.....much less than a 60Da. For planets you'll want a telescope and webcam, the mount mentioned above may not be beefy enough. You don't need a large scope but you do need a good mount. The mount above, with an older, modified camera would set you back well under $1,000. You could get a refurb 60D from Canon for cheap and have it modified to be the equivalent of a 60Da for far less than the price of a 60Da, but for that matter a T2i has the same sensor and will work the same when modified, a T3i would also give you the articulating LCD. I've done planetary work with the crop video mode on the 60D through a telescope - it works, but isn't quite as good as a webcam type imager. (I use a Philips SPC900NC). A non-modified camera will work and get you on the learning curve, it just won't work as well as a modified camera.
The three images below were taken ~9 years ago with a Digital Rebel (300D) and a Sigma 70-200/2.8, the M42 image with a Kenko 2X telextender attached. http://www.pbase.com/emagowan/image/23602641
M42 w/Sigma and 2X
In this discussion thread is a photo of a camera platform I put together from an old Celestron drive base and a tripod head. Looks like a cross between Frankenstein and Rube Goldberg but it does the trick.http://www.canonrumors.com/forum/index.php?topic=12499.30
These mounts and others similar to it can often be found for reasonable prices at:http://www.astronomy-mall.com/astro.parts.outlet/list.htm
If you have a local astronomy club, by all means join it. The one I belong to has a number of loaner scopes that people can check out for a month, great way to get your feet wet for cheap. You'll also find a bunch of folks who will be more than happy to bend your ear if you have questions. We have a potentially spectacular comet headed our way late this year, get some practice in now and you'll be able to capture some fine images when it arrives.