Warlord, its fine ... the PAF Pro is fine! But if you intend to use the neck pup (or ANY neck pup for that matter) for heavy chords, you'll never ever get the crunch and clarity that a bridge pup will give you.
Do not stereotype pup in that, the neck pup is for this ,the bridge is only for this and so on, so forth.
The bridge pup can be used for rhythm or lead. The neck pup can be used for rhythm or lead. The middle pup can be used for rhythm or lead. Its in your hands, its up to you and the music.
Stick to your idea of TZ, HS2 and PAF Pro first... that sounds fine so far since you are going to be using a high gain amp already.
Fruitwine, there will be a volume different between the HS2 and the humbuckers, and that adds to the versatility of a guitar. If your guitar's HSH pups are all hi output, you will get a nice even volume thru out, but try doing some bright spanky cleans. Or try to get that abt-to-break-up tone. Its just harder.
Moreover, if ppl want hi gain, they only use the neck or bright most of the time...
IMO, in that case, the middle single coil should be something different, to add to a guitar's versatility.