Definately not an expert here but I bought a 25kg sack of IMC pale and it is going well. Haven't tried Joe White would be interested if people think it is better.
At the end of the day I would try a test brew using the grain you think you want to buy in bulk to make sure you are happy with the results.
Well, living where you are you must be used to stuff costing heaps
No HBS in Perth you could pick grain up from?
No kidding, cost of shipping malt is a killer, like $200+ for, ummm, 10 sacks of malt from Melbourne to Adelaide. thank God I have a closer source now for all but the special specialty grains
joe white also have export pilsner batz.
thats another option. it is made to the highest lager malt specs for heiniken etc.
so it may well be one of the most used base malts.
anyway my vote goes to the traditionl ale malt.
i have heard that the imc ale has slighty better attenuation than the JW ale. i have found them to be around about the same malt.
another few options if your want to make a tree hugger beer you can get organic malt as well.
the new mountain goat i.p.a uses all organic produce.
still haven't found this beer in s.a yet but am waiting for a taste of this tree hugging hippie beer.
grumpy Andrew tried this malt and said you should really use irish moss in the boil with it. i haven't use the hippie malt yet myself.