I've done the full swap ,
Didn't bother with the longer wheel arch , never had an issue
The bumper Guides I got with the bumper , best place is eBay for them .
Also my grills where already in the bumper but I think they are a fair price . and wouldn't get new much cheaper unless you get used , also just incase you haven't realised . The centre grill with the seat "S" badge in is also unique to the R bumper they are a different shape and size from other
Bumpers