Congratulations on your purchase. To be honest I like the original rims that go with it, but that is up to you. You can either upgrade them to the latest TR rims or 512TR rims as you indicated. I am not sure which will all fit, but I assume BBS and the like will all have rims available. Maybe even Hamann motorsports. I think your best bet will be Germany, since many 'tuners' are located there!
Niels
Niels