Don't remember what I used, but I think they are 3" and didn't cost $150. But it has been 5-10 years since I bought them so who knows what has happened since then. I know I struggled to find the right studs though, so there could be even less options than when I did it. Have to keep that in mind if I do up another set, pulled a set of old rotors to make another set and was thinking about it.
I don't really like aluminum hubs for the street. Plenty are running them so probably not an issue, just makes me nervous.
And I think his hubs set the rotor further out than the hub machined from stock rotors do. No idea how much though,
@72bluNblu said it wasn't much. Would have changed how much shim material you would have needed, but probably not much of an issue.