At the time I bought my Tig which cost nearly $1000 and is ACDC so can do Ally, SS etc , I couldn't afford one with a foot pedal, I can convert it but will be a on/off instead of progressive.
Electrodes are red or blue top mainly, there's not much between them. When practicing it's best to have a bunch on hand already sharpened up cause once you dip is walk if shame to the belt sander. The best tip is have electrodes at or less thickness than the metal your welding. Also those clear cups are great to see more in tricky spots.
Practice on different thicknesses and write down your settings so it's easier to go to later , tho it's usually 1amp for every thou, 0.040th =40amp etc as a base line and pure argon for gas, not argonshield
Mark A , I suggest to get the best you can which will do all metals cause you never know when you'll need to make it fix an ally sump or stainless zorst system..
The supplier I use is in Perth, Hampdon welding, they sell stuff as good as boc etc but easy less price.
I buy the filler rods (also at the metal thickness of less) from them by the kilo, metal, alloy, SS, also silicon bronze for mixing such metals .