I've been looking at options for which camera to go with so I can get the images from the grating...  I am leaning toward modifying an existing webcam so I can take long exposures...(this will allow for getting a better image since the return light passing through the filters, etc. will be fairly weak.) .  So, a little googling lead me to http://www.pmdo.com/wwhich.htm which has a great list of mods people have done to cameras for astronomy...  Looks promising... 

The other option was to use the standard raspberryPi camera board..  This became less appealing after investigating the exposure settings and testing with a small spectroscope in the lab...  Not great...  Ok, but not great...and some googling lead to finding some difficulty they've been having with longer exposures.....I'd like to use it, but if I do...I might actually go with the infraRed version for a secondary setup where I can take IR exposures in addition to the regular stuff...

The cameras listed on the above link, mostly seem pretty lo-res, older cameras...I'm still pretty early on in looking into this, so I'm going to do some more reading and see if I can just mod a camera that I like...I don't know if webcams are like the ccd's they use in astronomy, where they need to be cooled, etc. for long exposures, but that shouldn't be a problem..

More on this soon! 

Update: I think image stacking is probably looking more attractive at this point..  

http://blog.wolfram.com/2010/12/27/fixing-bad-astrophotography-using-mathematica-8-and-advanced-image-deconvolution/

Update: Looks like I'm thinking the raspberryPi camera module is still a good option....shooting high frame rate video for a period of time...then splitting that into a number of images, then stacking those to create one simulated long exposure image for further processing...  I will experiment with this approach soon...