The older two cycle lawn boys are awesome mowers! I personally love them. Nothing wrong with starting with them and as the guy above mentioned the coils are a pretty common failure and they're kind of hard to find but you can find a few on ebay.
I personally have two of the Toro suzuki two cycle 21's and love them. They're pretty fuel efficient and cut great imo. You won't be able to bang out a ton of lawns using 21's unless the lawns in your area are small but they will get the job done.
-1996 RAM2500 Cummins 12V
-H&H Spray 200 gallon skid sprayer
-Billy goat TR500 5HP leaf loader
-Gravely Pro turn 52in w/23hp Kohler EFI
-Gravely pro hydro 36in walk behind
-Toro proline 21" suzuki two stroke
-Stihl BR600 Magnum
-Stihl BR420C Magnum
-Stihl SG20 backpack sprayer
-Bluebird 530 aerator with 4HP honda
-Prizelawn Bigfoot SS spreader
-Homelite hedge trimmers