Strictly speaking, you ought to take 4 runs, one "straight" with no filter at all, and then one for each of the 3 filters. The first one, i.e. with no filters, gives you Luminance, and the other three runs give you the colours.
In practice I never bother with the L run, but it's possible that you can get a lower noise result if you did.
Umm, good question...glad you asked...looking...looking... nope, can't see them. Maybe they don't sell them after all? You could try ringing them and ask - maybe they can put you onto someone?