Thanks for the comments guys. It's hard to say how they'll look until they're actually on the car, but I reckon it should work nicely. FWIW they're the same size and a similar style to the Simmons on Paul Pyyvaara's 2JZ Supra, and it looks hot!
I got one thing wrong though, they're actually 5x114.3, not 4x114.3. That means I'll have to fast-track my 5-stud conversion! Lucky for me I just fount a pair of MS65 Crown hubs (5-stud and direct bolt on) so that's at least half sorted now.
They look like bigger versions of my Hayashi 5 spokes Norb, very nice. So what are you going to do about the rear 5 studs? Has anyone had any luck converting those yet? Since your wheels have center caps, at least for the rear you can drill the other 3 holes and weld up one of the old ones and they will still look good.
I'm using Kings springs, about AU$300 for the set. As for the rear hubs, apparently MS123 Crown hubs will fit with "some work", although I don't know anyone who's actually done it. I'll be giving it a try soon though, so I'll keep you all posted.