OZ wheels are very strong. Like Maglines. But super-costly for it. But Humps, what's come out of this exercise, in view of Lee's insights into the weight of 16" 6-spoke SE wheels, is that you'd be hard-pressed to do better than those 16" 6-spoke wheels anyway, at least for half-sensible money. This is perhaps contrary to Schnelltrecker's info - if I understood him correctly - that the 6-spoke wheels are 'heavy' which is why I questioned the weight. But Lee has actually weighed one...
The wheel-tyre combination on 195 16 6-spokes is 16kg a unit. By comparison Ultraleggeras and Maglines, albeit and crucially on 215 rubber, are only weighing in at about 1kg each less. 1.6kg less in the case of your desired 16" Ultras, perhaps over 2kgs total if you run 195 or 205 tyres. That's not much for the near £1000 outlay! As much as 215 rubber has obvious performance advantages 195 gives the A2 character and feel and, in my view, is just fine. At least with up to 100bhp.
The fact remains that most people buy alloys for vanity reasons and compromise the ride and handling of their cars (relatively speaking) in the process. Especially when going to 18". People who have 17"TT wheel and tyres combos on A2s are lugging around an incredible 21.7kgs a unit, more if on 225 treads... That's where the Comp TT (Parabols) seem relatively light at 18.3kgs, tyred on 215s.
I've been round the houses on this, and will now be sticking with my 6-spoke 16s and 195 tyres.
IMPORTANT NOTE: all these weights (tyres and wheels) are 'to the best of my recently accrued and variable-quality knowledge'. And Lee's 6-spoke weights are pivotal to the whole argument! No doubt others will have differing views...!