how much front camber before the tyres wear on the inside bad??

 

Depends how you drive it.

You might want to look at increasing castor rather than camber ... it gives "dynamic" camber when you need it, but little when you don't. It might make steering a little heavier ... but probably not much.

I haven't seen a castor kit for our cars ... i'd definitely be interested in one though.

 

i think Kmac makes a camber/caster kit for our cars, my friend has one

 

kmac makes a camber kit - yes. Caster - I'm pretty sure they don't. I recently asked them & Whiteline, but neither had them.