25mm is alittle much?! 15mm would probably the thickest without risking integrity. also be sure that these spacers are hub centric any other spacer will not allow your wheel to seat properly against the hub and eventually loosen and fall off. as far as lugs go i would compare your stock lug and wheel setup to see how far the lug actually threads into the rotor and then be sure the new lug threads as close to oem as possible better more than less but as you found out the hard way, to far messes up the brakes.