Whats the best (simplest & cheapest) way to buy DNA Stage 2, & Kev Mods?

Does anyone stock locally or is it getting both through whatever channel?

Kev I see has his mod on Ebay where he is offering the fuel controller and O2 Controller.
DNA offer theirs through OTR, and I coldnt find the OTR Foam (removable) filter for dusty conditions - anyone any ideas?

Many thanks