I had a 78 Suburban with the FF / Positron II combo and I loved it. It was an excellent chore bike, solid comfortable, full length fenders, shift without peddling, too bad yours is too small. That said there are tons of decent affordable frames. Something like a Schwinn Continental or World Sport (cro-molly), or maybe a Panasonic, Trek would be nice. Raleigh made a ton of steel frames, a Raleigh Super course has Reynolds 531 main tubes and can be had at a reasonable price.
How small is your suburban? I assume you probably ride 60cm - 63cm frames pretty comfortably. The electro-forged Schwinns get cracked on sometimes, but for flat landed Ohio cities they are great. I have had a Collegiate and a Suburban and I will say that the Suburban rode way way better. The suburban has bigger rims and tubular forks, not sure if the gearing was any different though. Ok, I am too far off topic, simply put, there are is a myriad of fantastic mid-range vintage bikes.
I have a 78 Raleigh Competition frame that is 63cm, the frame is full reynolds 531 with campy dropouts. It has a kinked top tube and needs painted. I don't know if it can be fixed or if it is worth it, if the experts say it can be fixed I would give you the frame and fork for the price of shipping.
-Matt
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