First off, I second the Digitech Drop pedal, I play along with all sorts of tunings, so it's a godsend! Unless, you are ONLY going to play stuff that's tuned down 1 step, then just get your 540 setup for that.
Sorry if I'm hijacking, but it looks like the OPs questions were answered and I didn't want to start a whole new thread about the same guitar.
Questions about 540 pickups -
I got an S540LTD back in October, it's either a 93 or 94, serial starts with F93 but he said he got it for his 15th b-day in 94. Either way, he was the original owner, it's Jewel Blue, mint, and got it for $500! From what I understand, the IBZ/USA pups were basically Ibanez-branded DiMarzios? If so, what models would the F1/F2 be most similar too?
Also, I am liking this guitar so much that I'm looking for other 540s from the 90s (as long as they have the AANJ and Lo-Pro) and noticed that the later ones have QM1/QM2 pups, what can you guys tell me about those (in general and vs the F1/F2s)?
And I guess any info about known, or potential, issues with these 90s S540s is appreciated! Thx