The air flters will be B&S parts - no problem with them. The belts will be a standard length - if yours are intact, measure them and order by length. If not, use string round the pulleys, measure that and add 1 inch. Afraid I can't help with the bearing, but if it's a standard size (and removeable/accessible), there are any number of bearing suppliers out there.
phil_saunders(a)bigfoot.com
Phil Saunders
June 2012