thanks for the info, i have passed it on to him and he seems keen on the rock shox xc .. can not find a supplier in uk for the 80mm version, but seems happy to deal with the company you listed he has e-mailed them today,once again thanks for the help..
No problem. I know it is not a question you asked, but before ordering, if not already your friend might want to think through the technical implications of a switch.
Apart from needing new headset/spacers and stem, if the bike is fairly original and has canti up front it will have to be swapped to a V brake, because with suspension forks the only place you can put a hanger is on the brace/arch between the lowers, and most modern forks don't have the facility for it. The knock on effect of that is that new brake lever is also required because canti's and V's require different cable pull. If they are brifters then a new brifter will be required.
Given the switch is not exactly a simple undertaking, it is worth doing it properly if at all in my view. RS XC's come in
different versions, the cheapest are only adjustable insofar as spring rate can be changed by swapping springs, which is not exactly easy and cheap (and which is why I said it is the least worst option). Hence if the rider is not of "standard" weight, air forks which have infinitely adjustable spring rate while more expensive may actually work out better value in the longer run. Also better forks have adjustable damping, which is pretty essential for reasonable offroad performance. This is why I can't understand why anybody would suggest going to all the trouble and putting some cheap
pogo stick Suntour on a bike...
One final suggestion, is if the existing tyres are not fat or suitably pressured, a pair of good, fat (over 2" if the forks/frame can accommodate) tyres on with suitably low pressure may well deliver the improved offroad performance that is desired without messing with the forks. It is an inexpensive, great, lightweight solution/opportunity many miss.