Big Bend is as bad as Beck as far as launches go. There is a way to load and unload a 14' or smaller aluminum boat that requires no or very little contact with the water. You have to unhitch your trailer and push the boat off while allowing the tongue to come up in the air until the boat slides to contact the ground, if you do this with half a brain and carefully it works really well. Then when the tongue is way up and the transom is on the ground you can begin to pull the boat off while holding the tongue down. The boat slides off if done slowly and carefully. You can reload by backing the trailer to the front of the boat, hooking up the wench, and reverse the process. Reloading is much easier. Trust me, it sounds crazy, but I've done it with a 15' deep V Alumicraft and its not that difficult IF done slowly and carefully.
Anyway, I don't know of any decent fisheries around our area for boats other than Opeka and those mentioned.
Oh, small tires aren't the issue, it's tread size/thickness. I forget exactly, but you need to get a certain tread that is heftier for highway travel (up to 65mph or so). It has to do with temperatures and seperation of the tread from the radials or something. :? The have them for smaller trailer tires, but they're about 120.00 plus for the pair installed on the rims. I went to the place on Oakton near Elmhurst road. Eberhardt's I think is the name. Their ok, not all that helpful but at least their close and will do the work for you.