I've had a few engines machined by best machine and a couple assembled by them(shawn).Last summer he did a guy I know- small block stroker (st clair engines),after I installed the engine,he showed up for the break in.valve lash, basic tune.So all involved knew break-in and set up was right.Very knowlegable/capable person imo .You can go to 5 different builders/they will all have there own recipe.doesn't mean 1 is better/worse than the other.They need to stand behind there work,so they will build it the way they are comfortable with.You probably need 6 weeks or so, for the work to get done.You better get going . All the places you are considering will be ok.Go with the one you feel most comfortable with.No place is gonna have a perfect feedback.Someone is going to have a bad experience with 1 or the other.For the money invested, overbuild and be safe.saving a couple $$ here and there could bite you back.
I was happy with the work custom speed did for me years back also.