Think my chain is knackered, gear shifting is perfect but gears are slipping when pushing hard.

Would I have any probs running an SRAM cassette instead of another XT, and if I did go SRAM would it be better to get an SRAM chain?

i have always run sram chains with shimano cassettes, i have never had any problems with this combination so IMO it should be fine.

Like Funkyhooda said, As long as its 9 speed XTR you will be fine.

Its fine I run that cassette with a KMC chain and XTR everything else no worries. I've broken SRAM chains and much prefer the KMC although there are good deals on XTR chains at CRC right now.

as joolsburger
my fav combination is Sram cassette, XTR mech and KMC chain