Arch is the only way to go.
I use an arch similar to the one in the pics posted earlier (ASEMASTER)... Sorry no pics. The differences between ours and the one in the pic....
We used square tube and there is an A frame above the wheels (3.5 ft that a pully block sits in. A horizontal tube connects at the top of the A creating a 12" triangle. Ours is slightly longer.... We use a boat winch in about the same position as the one in the pic. Wrap the log, lift it 8 - 12" off the ground. Then use a chain from the log to the frame of the arch near the winch (again almost horizontal with the chain). This transfers your pulling power mainly into the chain..... your winch line is just used to keep the log up.
You'd be surprised what you can pull out of the bush this way....I would estimate 3-4 times what you can pull without an arch, also far less dirt on the log.
When my arch makes it home (friends got it) I'll send you some pics.