Ok, here's what I've learned. A two stage regulator is supposed to help with possible breathing of the torch flame but there isn't a whole lot of consensus on that as breathing can also be caused by an oxycon or other mysterious reasons.
I went with a propane regulator (that can also be used with acetylene) because it made sense to me to have one with components made for corrosive propane. Plus my last regulator (a good quality brand) stopped working even though I only used it for 2 years and have had it in climate controlled storage ever since. However maybe the materials simply degraded from age as I bought it in 06!
I plan to take it to a welding shop once I can find one to see if they can service it. (The closest one I've found so far is very far away so not really an option for me.) I'll be curious to see what they tell me is wrong with it.
The hard part now is waiting until the regulator gets here in a few days. Then I have company visiting from out of town the same day it arrives so can't torch then. Argh! Oh, lord, the anticipation is already driving me crazy!
The biggest reason I rented this duplex where I live is because it has a garage so that I can torch. (Renting's a pain that way.) But maybe that helps to explain how big a priority lampworking again is to me!
Cheers!