Hi Cris,
Yes, you are right. I had to order bits from Far Circuits. I should have ordered the rest from Jamaco and problem solved. But encoders that you mention from US Digital are quite expensive. I don't know what CPR you have, but I would go with 2500 to make 10 000 (4x). And they are $90 US plus delivery. If you buy them from Garry he sells 10 000 ones with the kit for my scope for $288.10 delivered.
From my experience, every time I try to do something cheaper I end up paying more at the end
I made big mistake when I had chance to get EQ6 GoTo for $1000 a few weeks ago. I thought it would be awkward to use it with my 12" Bintel but then I saw this website with custom made pier:
http://www.epsilon-telescopes.co.uk/services.php
Scroll all the way down to see the pic.
cheers