Zero advantage to the Variflame system as far as I can tell. Personally, I’d just get a Bh209 plug for half the cost. I’d stick with 209s - easier, simpler and just as reliable. (BTW, I have over 30 muzzies of several brands and I shoot everything from black to smokeless and bullets from 175 gr to 600 grs and #11s/209s/LRMPs.)
LRMPs have a slightly hotter flame temp but only about half the flame volume of a 209.
Muzzies can be really hard on cheap scopes, I’d upgrade to a decent scope for sure.
You will most likely need an adjustable sizing die to size jacketed .45 bullets for your bore if shooting bullet-to-bore. And your barrel may or may not be consistent enough to do that. Some are and some aren’t. You’ll have to experiment.
I’ve used all the bullets you mention - I’d start with the Furies. Great shooting bullets and cheaper than many of the others. Good luck!