Inner c.v boot failure is super common on any lowered P1 chassis.
My C30 destroys at least 1 driveshaft about every 12months so I usually get 2nd hand genuine shafts and fit new boots myself. Sandwood trading in Melbourne keep good quality aftermarket boot kits in stock.
The quality of the aftermarket c.v joints isn't as good as the genuine Volvo joints and I would avoid in a highly modified car, i recently replaced the r/h driveshaft with a reconditioned shaft and it's already noisy less than 6months later.
The inner c.v is burred over so usually needs to be carefully cleaned up to remove the tripod.
Im looking at getting these upgraded driveshafts soon as im worried next time the L/h fails it could take out the gearbox housing
http://wolfracingproducts.com.au/dsci-motorsport-s7-driveshafts-ford-focus-st225-xr5.html