a GTiR maf is something like a diameter of 45mm whereas an SR20DE (P11/N15) has a diameter of 70mm. If i were you, id get one of them, alot easier to come by, alot cheaper and better flow.
When my brother upgraded the MAF on his highport autech (similar MAF to a GTiR) to an N15 GTI MAF, it made more power instantly without mapping due to the better flow and made more after mapping.