Any shops in Vic that have stuff in stock. Happy to pay a premium if I can try before I buy.
What part of VIC are you in? Regional? Melbourne? Which Part?
The Bike Exchange website lists 140 bike shops in Vic, but you can also put body armour into the search line and specify Vic, etc
Ultimately you will probably need to look up the manufacturer's website size charts and carefully measure your arm/leg/chest etc etc.
There will be MUCH greater choice online.
POC
ION
FOX (esp Launch Pro D30 (with the replaceable? plastic slider cap)
IXS
Alpinestars mtb and moto armour Chest/Back/Shoulder/elbow armour shirts
.
Dainese mtb and moto armour Chest/Back/Shoulder/elbow armour tops.
EVOC make great bike packs that have a removeable back protector, and come in at least 2 sizes. Also Chest/Back/Shoulder armour tops.
IMO, Look to the brands that do Moto armour for armoured gloves. If you don't know what to get, go for the Fox Bomber moto gloves with hard knuckle and finger joint coverage. Try them on at a moto/motorcycle shop. Ring them first to make sure they actually have them and in the size.
Great coverage and fit, but get the size right, as with any armour.
Full coverage upper body moto armour is generally the most protective, but if doing anything other than shuttle/chairlift days, you can be pouring sweat, and even then. Dainese and Alpinestars, and IXS all make short sleeve MTB armour shirts. with chest, back, and shoulders.
Get the ones with a Zip for easier on/off, IMO. Try getting into and out of a eg Troy lee armour shirt - with no zip, it can be a struggle. if it's easy, it's too big, and the pads won't sit where they need to be.