SP Engineering is definately a big name shop. But I think they do mostly Mk. IVs. They've got a dyno. Didn't they build Kenny Henderson's Mk IV monster?
Toysport in Gardena specializes in Toyotas. I did business with them for a while. They don't stock a lot of stuff, but they can get it if its available and its mainstream HKS, Greddy, and so forth stuff. They also build street and race cars. But they don't know a lot about Mk.IIIs and the shop is real small.
They do phone orders too. Joey's the owner. He has good general knowledge about Toyotas and how to build them. The guy that does the phone orders was real knowledgeable about the products out in the market. But some of the mechanics working there were not real mechanics.
http://www.toysport.com/
Top-End -Performance in North Hollywood. But I think they only have serious racing stuff like stand alones and full racing builds. I got a water injector unit from them. They love 7MGTEs.
http://www.racetep.com/
Right now, I do business mostly with Jeff at HPF. They've got good pricing, realllllll helpful and a large selection.
I did do some business with Rod Millen or was it Steve Millen. One's in Huntington Beach and the others in Costa Mesa. Neither one of them specialize in Toyotas of any variety. But they can fabricate anything and I think they both have dyno's.
If you want to dyno a car, I'd take it to XS Engineering in Huntington Beach. They built some of the cars in the Fast and Furious. But they too don't specialize in any specific vehicle much less a Mk III. They've even got a 4-wheel dyno.
I think most "speed shops" don't specialize in any particular vehicle. They just order what you want. So I just stick to Jeff at HPF for now.