This sounds great to me - I would use some of zefir's kind donation towards this as well. I didn't want to spend too much on it but if it's shared amongst a few then it's quite workable. I think a good 100MHz Dual trace (1 or 2 GSs) model would be ideal. My reading so far seems to indicate the Rigol 50 or 100MHz models are much favoured due to their deeper storage memory. I view having one as a hedge against problems arising later. It's probably possible to just use my Logic Analyser but a scope would allow much more thorough diagnostics, particularly on the power supply.

The Hong Kong / China sellers who use EMS are well situated to get one here fast enough and without terribly ridiculous shipping fees. I'm going to do some more reading now and try to narrow it down. There is some local sellers as well and I'll have a look but typically they sell stuff like this for 50% higher than the online price.