So astrovideo – you want to see some stuff live on a monitor or computer. For astrovideo you need a goto mount, otherwise very difficult (but some do it on a dob with a lot of focal reduction). Most people use an alt-az mount as easier to use, and fine as you only need to take 5-20sec shots and stack them over a few minutes.
The camera depends if you want to just plug into a monitor or go via a computer.
Via monitor you can go with the likes of the revolution imager, or some sort of mallincam. But these won’t be cheap as you’ll have to import from USA. There aren't any decent cameras out there with HMDI for astrovideo. The drawback is resolution with these. If you want to plug that through a computer the resolution of the analog-USB devices is terrible.
Via computer. The IMX224 colour based cameras are all the rage. Bintel for $420 is the ZWO ASI224MC (make sure you get one with a version 1.3 board, not the older 1.2, as the new one as amp glow reduction circuitry). On aliexpress Rising Tech have a clone which is even cheaper. You'll need a computer - rising tech has their own software, or use the free(ish)ware sharpcap. Both have excellent stacking software and you'll get some nice live images within a minute or two depending on the object.
Either way, you'll need some focal reduction (what Fratio is your dob?) to get a faster images and larger field of view. You can start with a cheapie x0.5 from Bintel or anywhere. This is OK with the small 1/3" sensors – astrovideo doesn’t care about coma etc on the edges.
Definitely have a look here
http://astrovideoforum.proboards.com/ and
http://www.cloudynights.com/forum/73...ted-astronomy/
These are dedicated to astrovideo. Its live imaging, nO astrophotography post-processing on these sites.