How handy are you? If you don't mind a little cutting and drilling, you can make a pretty good trailer. Can you get it locally and not pay shipping?
1st thing you should do is disassemble the leaf springs and take all but the longest one out. The trailer will squat 3-4 inches when you stand on it. This is what you want. The KH and the trailex are set up like this, but their springs are a little longer.
You should really try to come up with some type of gunwale support. If you have, or know someone with a welder, that could be helpful also. I'm sure you know by now that bunks are bad, but if the boat is a beater, then you could go that route. Or set it up for deck-down trailering.