I know what you mean about building something different, and I'm guessing you don't have a 502 caddy just lying around. 307s are fun to play with, but if I was hauling a load or pulling a trailor I would want at least 350 cubes under the hood. That said, 307s are cheap and fun to build because they respond well to smaller parts that most people don't want. 305 1.84 valve heads work well with their small chambers and larger ports, and are very cheap on ebay. Same for 283 powerpack heads. These heads will choke a 350 but are just right for a 307. The best setup I've had on mine so far is 461 camel humps w/1.94s and .030" milled off, edelbrock c3bx intake that was virtually left for dead in my garage, duntov 30/30 solid cam, and 600cfm carb. I've rebuilt this motor several times, and I'm finding out the smaller I go the better it seems to run. No single plane intakes, 2" spacers or 750 carbs. Also, you'll either want to get an msd blaster2 coil or replace points dist with an HEI.
Friend of mine had one in an 80s camaro with a saginaw 4spd behind it. When he got it revvin it would plant you in the seat. Definitly liked the 4spd. We seen the car at the track a few years after he sold it, and found out people had been passing it off as a 327.