I have been looking for a replacement tyre for the Khumo's. I considered R888's, but wanted some a bit better in the wet, and priced south of £400.
After a bit of research on the Interweb I came across a lot of posts from various forums extolling the virtues of Federal track day tryes,
in particular the Federal 595RS-R. Almost the same grip, better in the wet and around £200 a set delivered.
So I ordered a set

There are a few out there that are less well know and seem good value for money. Not sure about how good they are, here's another http://www.tyreleader.co.uk/car-tyres/nankang/ns-2r/195-50-r15-82w-247439?utm_source=compare%26utm_medium=google-shopping%26utm_campaign=tyre&gcli d=CLT5lvTSqLwCFdQPtAodTkoACw

I have the federal rsr's on my Mk Indy R1 and I personally think they are great, especially when they have warmed up. Can't fault them for the money. Enjoy.