Buddy of mine just had his Fountain done 2 weeks ago, used a guy named Keith, he does all fiberglass work for Coty Marine and Ocean Beach Marina. I'll try and get his number, guy did great work, wasn't super quick but did it well and had 0 idea hos to price materials so it was much cheaper then other places in the area by a bit.
Regardless of who you use, ask them how they plan to do the work, what materials, are they using West system Epoxy's, good quality fiberglass matt and the right wood if they are using wood, or are they using core and glass, find out then ask Grady if they think the materials being used are strong enough for the repair. Ask them how they plan to tie the new transom into the stringers since this is where your force is applied and spread to the hull and takes the most beating. Make sure the guy knows what he is doing, he should know his material's and what not off the top of his head, or be able to get a proposal to you quickly. Make sure they aren't just drying the wood out and filling the void, you will get ripped off and that is not a true fix, just a give me another year or two method, the only proper way is to remove the transom and replace it with quality materials and have it sealed properly to avoid damage down the road. Any thru hulls and scuppers should be protected and treated where they pass through the hull and anything below the waterline should use 5200 adhesive. If you have a tranducer mounted on the back of the hull make sure you have 4200 or 5200 in the holes to keep them water tight and protected, silicone and other chaulks aren't going to cut it over time and this is where many wood hulls begin to have issues.
I have heard good things about Raybo. I would recommend them, had a buddy have work by them a few season's ago and they were highly pleased. also, Dr. Gelcoat in Port monmouth NJ does the job, but he isn't cheap. We built us a hatch cover for over the battery well on our 22 sefarer, a crew member forgot to cover it and it bounced overboard, you could not tell the difference between the 2 cover's, non skid pattern matched perfect as well. They are a smaller shop and always busy so having it done quickly may or may not happen, do not know if they have a wait.
Regardless, get a few qoutes, if one's cheaper, have him explain why....explain his materials and such and find out why, is he using 1 less layer of mat, cheaper materials or maybe he is legit.