i think that bracket is totally convertible, that's the beauty of metal, damn near anything is possible.
as far as a welder, i wouldn't use anything that wasn't a Miller others are good, that's just were my loyalties are
get one that runs 110 house current, thats plenty for anything on a bike (pretty much all the tube on these bikes is no thicker then 1/16")
my advise is to leave flux core wire alone until you've had some practice, i use it (at home) because it's cheaper, because then you don't need gas cylinder/flow-regulator/and related hoses ...
but there is no way your gonna wanna learn to weld with flux core, it's a serious pain in the ass for me , and i actually know what i'm doing
so if you wanna learn, don't half ass it :
good welder (a reputable brand so you can find parts for it easily)
gas cylinder (argon works best, but for MIG, CO2 is fine and a little cheaper i think)
flow-meter and pluming
a helmet with a dark lens ..say shade 12
thick gloves and lots and lots and lots of different clamps
i like my miller because it can run gas or flux core (not all of them can do both,look for "switchable polarity") so once you master it with gas , and feel like being a cheap ass, you can switch it over and use fluxcore