Well... basically....
It isnt bad, but does he know the performance tollerance's for these parts he will be installing?
I would even throw in a VALVE BODY as well if your going that all out.
So basically a converter alone is $500.
Labor: $800(pricey if you ask me)
Parts:
Valve body- $320
Kevlar bands and upgrades for AODE- $300 or so depending on who you purchase upgrade and overhaul kit from.
also...
Why do all that and not even upgrade your INPUT shaft, which is a biggg culprit when things snap in there!... cuz that breaks FIRST!
So another $200 or so...
Looks like you are above $2k already.
I would just look into buying a complete transmission from a reputable peformance company. I am sure others here with experience can shine in and point you to the right performance transmission dealer. As personally, I just use a AOD and let her rip and rebuilds are VERY cheap in my area.