I'm not even sure what a thrash metal pickup is.... No pickup is ever really distorted, unless it's malfunctioning. High-powered pickups used to be called distortion pickups because in theory they overloaded the tube preamp section of your amp. Some few people now use effects boxes, and even solid-state devices! Horrors... Jimi Hendrix and Buddy Holly used the same type of pickups, for what it's worth - that's why "Peggy Sue" and "Purple Haze" had the same guitar tone. :help:
The Lawrence L500 series is an exceptionally bright-sounding humbucker, Lawrence fiddled with the induction and other guts stuff so that you can get single coil-like clarity without it humming. An L500XL is the highest power, then the L500L, then the R then the C. You can always turn down the volume knob and '"trick" a high-powered pickup into acting like a less-powered pickup.... tone knobs work too! :headbang:
The advantage to me for using a higher powered pickup is if you're going to be using a parallel switch or even more importantly a coil tap, the extra power still gives you enough volume that you can balance the tapped pickup with the other one - this might not be important to you, but I tend to like to keep both pickups on and play with my knobs. :toothy11:
If you want a "creamier" PAF tone the Lawrence L450 or L600 (or whatever he's calling them this year) might be a better bet. He makes them in different strengths, widths and stuff, so you have to read a bit before ordering. There's some stuff here about using particular caps and 250K pots to trick Lawrence pickups into sounding as bland (ahem, "creamy") as PAF's:
http://p082.ezboard.com/fguitarsbyfenderfrm8.showMessage?topicID=298.topic
My personal feeling is, it's always easier to roll off highs that are there, than to wish that they were there and not have them at all.... :hello2: There's a fairly complicated difference between feeding a preamp a full spectrum signal and then rolling off the highs, vs. feeding a preamp a signal with the highs already rolled off - I prefer the former, but it's something to be fidgeted with over the years for sure.
http://www.youtube.com/watch?v=vGpr-Zy_wRs&feature=related