I fitted the 3mm slip on, hub centric spacers and longer wheel bolts this morning and I'm satisfied. The centre bore is perfect, the spacers tap on around the hub flange and then don't move, the mate is perfect and heaps of flange left for the wheel to centre on. Took her for a spin across the (legal ish) speed range and no wobbles or balance issues, happy with that.
I'll tackle the brakes on one of the upcoming long weekends assuming nothing more important pops up.
I went for Torq spacers and bolts from TM sold by 360link who was actually very helpful (and saved me some money in the process).