A list of websites of handy places for this trip.
ALSA – coach company. Run Oviedo to Covadonga. http://www.alsa.es/portal/site/Alsa
Their prices are pretty reasonable and the service, in my experience is excellent (raise your game, National Express!)
Oxigeno -outdoor shop in Oviedo, one which has helped out on both of my previous Picos trips
*note* the website doesn’t list the Manuel Pedregal address, only a larger out-of-town shop. I shall update this blog upon my return
Deportes Centeno -outdoor shop, near to Oxigeno