homelitejim
Full of Scrap
Skip the 610, find a 7-10, PM700. 70cc class, parts are everywhere, fairly cheap, runs a 24" bar easy enough, easy as pie to work on.
These old McCullochs are everywhere, they are cheap and will run a 24 inch bar with ease, parts are every where as most pieces of a 10-10 will bolt right up.
Try calling around to your local small engine shops to see if they have one out back, pawn shops occasionally will stock one(found my SP81 for $80 at a pawn shop) and your local craigslist. Don't be afraid of the 610, it may be heavy and bulky but it has enough torque to pull a 24 inch bar with ease and keep it oiled, I think it will even run a 28 inch bar if needed, plus can be had for around $100 or less. Other great cheap older models include Homelites Super Xl, 410, and 360, Poulans 306, 245A, and 3700, Echos 550, 610, and 650.