Reliable
Cheap
Fast
Pick two; the old golden rule
Any engine workshop can build an engine. Not saying Edge won't do a good job - by all accounts it sounds like they have a good rep - but a workshop that does exactly what the customer wants, regardless of how poorly thought out their choices for an application may be, and doesn't step in to say we've built heaps of these before and found that x works better than y...is only doing that build for the work.
There's a reason RP have the reputation they do and cars literally overflowing out of their workshop - it has nothing to do with not being able to do what the customer wants. It has everything to do with proven results and enough experience and customer base to say this is better, do this. You're the customer and there's a reason you're going to experts in the first place - they are experts. I don't know about you, but I'd rather an expert tell me I have it wrong and do it the right way because that's what I'm paying them for
But anyway, the kind of workshop you speak of sounds like it suits OP better anyway, as his rather extensive research into what parts he should acquire and years of building track monsters with them will suit the kind of workshop who will meet a customer request without challenging it