heres one train of thought. im sure youll get plenty of offers.
my dyno is in my sig.
it had stock low end or better, and pulled clear to the top. it was done by jim @ passions. very usable power.
there are many builders to choose from, im not knocking any of them. you might find one by where you live to you can deal with them and what not.
basically call each or everyone you want to deal with, including the ones you mentioned and talk to them. ask them ?. tell them what or how you want the motor to respond. and you will have to read thru the bs. lot of smoke can be blown up someones ass.
remember your the customer, get what you want. some times ones motor might be more or ones cheaper, you just have to deside what you want. and how long you might have to wait for it. lot of builder are back logged over a month lately
you can do a search on most of the builders you want.
and get phone numbers for them.
hope it works out for you.