Re: New PU for Gibson Explorer Tremolo
With a Floyd, that should be a TB-5, but Custom is a good choice.
For thrash rhythm, Invader, TB-6 Distortion or PATB-2 Parallel Axis Distortion are great choices.
For thick riffs, Invader or PATB-2 are a bit better. A lot of people have trouble getting leads & rhythms balanced on the Invader without adjusting controls on both guitar & amp. There are people who pull it off, though.
Distortion does a bit better for leads, but I like the PATB-2 even better, as it has a less harsh high end, while still having the prominent upper mids of the Distortion wind. PATB-2 might be thicker than you want in an Explorer, depends on the guitar.
TB-5 Custom is a great all-around pickup that can handle rock to thrash very well. Doesn't have the crazy upper mids of the above mentioned pickups, but it's more flexible in exchange. Custom is probably more suited to Maiden than the Distortions or Invader.
JB can be a bit loose in a floyded guitar, unless it's a tight, bright guitar like a long scale neck-through superstrat. Not my first choice for most Gibsons, though even there it has it's adherents.
You might also look at Gibson's Dirty Fingers or 500T (Hetfield used them in various other guitars/times than the Invader, until switching to EMGs).
I'd probably try the TB-5 Custom or TB-6 Distortion first, and exchange if they aren't quite what you want (or even buy/flip them used, they're popular models and easy to buy/sell used).
