Filters? Emgo, Hi Flo HF137, K&N KN137 for oil. Emgo or K&N for air filter.
Dealer filters are the same basic unit as Emgo, just cost a lot more. Order a years worth at a time if you have to mail order them. But, even NAPA carries K&N motorcycle filters, at least around here, including the KN137.
Anything else you source from Emgo is suspect, but even major Big 4 dealerships in WA got Emgo units from where I worked for the service bays to use. DIY types got Emgo filters in O.E.M. boxes...