Hi, I bought a 1999 Yz400f. I want to buy a stainless steel oil filter. It seems that I have only one choice: Ready Racing (Scotts does not offer one for the 99 model). Anyway, I wanted to ask your feedbacks about the quality of this filter. Should I buy the cover with it or it's useless? Also, I saw on their website that they offer cheap air filter. Anyone has any comments on those filters? Thanks in advance for your help, it's my first four-stroke so I have many questions in mind!