I use a C8 for imaging at times. You could get a Crayford to potentially elimimate focus shift, but keep in mind it will add a fair amount of weight to the back end. I have one. Wife bought it for me but I've not used it due to weight. If you have a beefy enough mount, might work, but you *may* also have to add a SCT counter weight to the front - something like this perhaps: https://www.buyteles...il-clamp-174487
Or just make sure with the existing focuser and be prepared.
Bahtinov mask - essential for focus.
To use 2" filter - get a 2" visual back and a 2" t-thread adapter (such as: https://www.telescop...r/p/113926.uts)
Your DSLR can then attach to that adapter. Or, if you are using a CMOS camera that normally would slide into a 1.25" EP socket, you can get one of these: https://www.amazon.c...85294781&sr=8-9
I would also suggest checking astrobin.com and see what people do with C8's.
Good luck and clearer skies than I'm having right now.