Schedule 80 Nipples

I have a 50+ year old Ranch house plumbed with copper horizontal and risers. At each fixture there is a Brass 90 with Galvanized Nipples and standard cutoffs. My plan is to replace all the standard valves with 1/4 turn ball valve cutoffs. Since the nipples are rusty (of course), my plan was to go with Bra$$. Each 4" nipple costs about $6.00. I picked up Schedule 80 Nipples (grey) for $1.00 each.
I have never worked with Schedule 80 Nipples.
Are they suitable replacement for Galvanized?
Teflon Tape? Dope?

Stay with copper/brass. PVC can break. Tape vs dope is a frequent question here. Some of us prefer just dope, some prefer tape, some prefer both. I have had excellent results with just dope.

A sch. 80 PVC nipple WILL snap at the threads, just like a male adapter, it just takes a bit more stress. NEVER use PVC of any kind inside the building.