Ah, well not so much experience with gathering rather with eating. Wattle seed pancakes or crepes are something else!
There's some seeds are more palatable than others and some species of wattle do better in some areas than others e.g.
Short of someone on BLF having first-hand experience, I suggest that you read some native plant books specifically the ones on edibles.
The earliest ones that I know from the modern era are by two local Botanists, the Cribbs. Alan was the Professor of Botany at Uni Qld and Joan was a Botanist in her own right and the daughter of two botanists. Their books published early '80s probably helped to popularise Australian native food plants. Their information is good and can be relied upon.
Finding their books now could be a challenge though. Sure to be some books written on indigenous food plants more recently.
"Several species of Acacias are more palatable and commercially viable, these being; Ac victoriae – Prickly Acacia; Ac. sophorae – Coastal Wattle; Ac retinodes – Wirilda; Ac coriacea – Dogwood; Ac murrayana – Colony Wattle; and Ac aneura – Mulga. In their natural habitats these species are plentiful, and because of this, they have been mainly harvested in the wild. The most sought after wattleseed is the Ac retinodes – Wirilda, which is now being planted in large commercial plots for the bushfood industry."
This is very useful:
"Several species have been used for commercial harvest for a variety of reasons: abundance of seed, ease of access, taste and ease to process. However, not all species are suitable for these applications or commercial production. The most popular species for commercial harvest are:
As for supplies: try HERE.