I'd think an 8x4 for your first flip starting efforts with only a prime. Once you get it starting and running out the prime you could move down to a 7x4 and a 1/2 oz tank of fuel for short break in runs. Try wooden props for flipping and handstarting -- they don't bite as hard.

Follow the link below for some great help from the makers of P.A.W. diesels:

[link=http://www.eifflaender.com/instruct.htm]P.A.W set and running instructions[/link]

Good luck and have fun.

Come back and let us know how you're managing with your CS .061D.