Don't know what you mean "different types" exactly. There are single and dual stage regulators, and of course the dual stage are more accurate with changing torch/ pressure conditions and larger and more expensive. In my opinion, unless you get really serious with "pro" every day work, single stage gauges are fine.
FOR CERTAIN GET SOME flashback arrestors (check valves) if they are not provided.
Tanks are going to depend on how they are handled in your area. "Most" of us decades ago when I got mine got 80 cf O2 and called them 60 Acet, but I don't thing that's the right term. Whatever is somewhat smaller looking than an 80 O2
If you think you'll use more just buy bigger.
Here I deal with Ox-Arc. A few years ago I feared I was gonna get stuck with tank pressure check fees, so I took my tanks in--even though both had a little gas--to trade them in. They told me they no longer "stick" customers for pressure check fees. So you might want to check into that.
Also "around here" there were some (large tanks) that were such as property of the RR, and if you bought a used tank, you-might-just-get-stuck with a tank which is essentially stolen. So go talk to the local suppliers and find out what you are up against
And Yeh........brand name, and Victor is it for me. Harris is also an old brand. Probably who-deals-what the most in your area is a good guide
