There was someone recently selling a never installed circa 1988 - 93 Buick Specific NOS (Nitrous Oxide Systems) system that included the factory style up pipe and everything needed in the Parts for sale forum. That kit was discontinued back in 93 or 94 I believe.
Back when I worked at Wynne Speed in Ms, we sold tons of these kits made by NX. These two kits will work, and can be jetted down low enough to help with spool up. You will need to drill and tap the nozzle into the up pipe just before the t-body.
Nitrous Express Hitman EFI
This is the base kit that is activated via a push button and comes with jets for up to a 75 hp shot and a 5 lb bottle.
If looking for more adjustability and a micro switch with larger solenoids, then this kit is it.
Nitrous Express GM EFI Race System
Honestly, for the best reliability and the best solenoids, I'd probably go with the second kit (GM EFI Race kit 20118) with a composite bottle and utilize a push button for activation and deactivation. NX is well known in the industry for reliability, as well as excellent Custom Service. I used to be on the phone with those guys 4 times a week ordering parts and calling for tech support. Great company, great bunch of guys.
Then again, what do I know about Nitrous?
Patrick