I have bedded four rifles, two of them twice. It is time consuming and attention to detail is a must. If it doesn't work out, you do it again. It is not something to be undertaken lightly, however, there is no way I would send anything other than a custom barreled long range rig to one of the experts. An excellent job can be done at home if you do your home work and have everything handy and available when you start.
I use Devcon steel epoxy, but consider Marine-Tex every bit as good. You will need lots of vinyl gloves, masking tape, paste wax, vinegar, Dremel bits, files and patience. Brownells sells extended action screws that make the job a lot easier. My first attempt was a Savage 110 .308 featherweight barrel hunting rifle and I didn't get the barrel low enough in the barrel channel. I Dremeled out a bunch of epoxy and lowered the action further into the stock the second time around. It consistently shoots quality ammo into 1" groups at 100 yards.
It was a learning experience which was helped by the fact that I wasn't willing to pay $300+ dollars to have a $350 rifle bedded.
Because you have a premium fiberglass stock and have never attempted this before I think having it hired out is a smart choice. Doan Trevor would be another great choice. Alex Sitman has built several long range rifles for me. I've never been disappointed.