Congrats on the Sol Cat purchase. I have an 18' too, it's great to be out on the water on something besides a Slowbie 16.

First, get your rudder release sorted out. You need these:

http://www.murrays.com/27-0257.html

For the transom, you should consider doing the repair yourself. Fiberglass isn't rocket science and a beach cat ain't the space shuttle. The main difference between a novice and expert fiberglass job is that the expert will use less material and add less weight to the boat without sacrificing repair strength.

Fair winds...