I suggest Arista Premium. IMO, it is the best amount of quality in a film for what you pay. You are getting Kodak Plus-X and Tri-X for half the normal price when you get this film.
Due to the cost of shipping to Australia, I suggest buying the film in a large batch to lower the cost per roll.
Bulk loading is hardly worth it monetarily these days, though it will save you a little. 18 rolls for $30 US as bulk film vs. 18 rolls for $40 US for pre-loaded cassettes does not seem worth it to me, especially shooting the volume you are shooting. My time is worth that $10 to me, plus I hate deciding when or when not to throw away old cassettes. It is nice if you are someone who would prefer shorter rolls of film (though I can't claim to personally understand the appeal of shorter rolls for anything I have ever shot).
If your chems are going off, I suggest syrupy concentrates instead of stock mixed from powder. HC-110 or Ilford Ilfotec HC are two examples. You can easily mix up 1 L batches of working solution each time you need to process. The concentrate itself lasts forever. At your rate, a liter bottle of Ilfotec HC will lasts you YEARS.
My two cents re: stop are to just buy a small bottle of the Indicator stuff, and consider it a long term investment rather than something with which to pinch pennies. Stop bath lasts so long that I would not bother skipping it or looking for alternative ways to mix it. In a recent post, I just figured that I am spending under one dollar per year on Kodak Indicator Stop Bath, and it sounds like I process and print way more than you do. Just filter your stop bath after each batch, and you can reuse it until it loses its acidity.
As for fixer, you are already using the one I was going to suggest. Ilford Rapid Fixer or Ilford Hypam are basically the same thing, but the Hypam allows you to add a hardener if you would like. Hardener is not necessary (nor is it recommended) for modern emulsions.
Washaid/Hypo Clear are worth using IMO, though you don't NEED them. They cut wash time, thus reduce the amount of water you use to wash your film. Time and water = money.