You really can't program a MAF to your mods, you can only program it to richen or lean-out the air-fuel ratio. If it is tailored for 19# injectors then its probably OK and probably a good deal. The headers really aren't that relevant when it comes to the MAF and its calibration.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black