Just put some 13" wheels on my Mk, They came with 160/535 r13 on the front and 170/575 r13 on the rear.

The rears are rubbing on the ouside of the wheel arch, mainly due to the offset being greater, however, the actual size of the wheel with the tyres is almost the same as the 15" wheels I have taken off.

I want to get some Toyo R888's or similar, what size would you all recommend? and what ride height is everyone running at?

Have you checked the camber settings on your rear wheels? It may be that you have positive camber which is causing the tyres to rub.... You also need to check your ride height and adjust as necessary.

You can also remove some of the material on the return edge of your wheel arch if required..............

Phil

Have a look here to find which size will suit you