Fender's "Parchment" color is actually much closer to pure white than most other "parchments" out there, including Duncan's. The Fender parchment is a very classy and beautiful color. Just a slightly soft/dingy white, while most other parchments out there are a bit sickly looking. It looks like white unless you have it next to something that is truly white. It just has a slightly softer appearance than bright white.
If you put a Duncan parchment pickup against Fender parchment, it will definitely stick out as being more yellow than the Fender plastic parts. IMO, if you have parchment Fender plastic parts, then you should get a white Duncan pickup. It will stick out, but less so than parchment. Also, the white will slightly yellow over the years, getting closer to Fender's parchment.
All that being said, it looks like the pickguard might be the only plastic part on your guitar that is actually parchment. It's hard to tell from photos that aren't professionally lit and color balanced, but it looks like the knobs, switch tip, and pickup covers and humbucker bobbins might be pure white.
FWIW, it's a gorgeous guitar. I've always wanted a white on white on white Strat (though I want it to be '50's style).
The PG bridge is the standard PG that Duncan has had for a long time. The PG+ was a pickup commissioned by Fender for OEM use, and used for a time (now replaced by the in-house Fender Diamondback, which AFAICT is basically a reverse-engineered PG+). It only appeared in new Fender guitars, i.e. it was not sold by Duncan to the public. The design goal of the PG+ was to have the same exact tone of a regular PG, but with slightly more output. Duncan thought that the best way to achieve this was to overwind the pickup and use an A5 magnet instead of A2. IMO, they were successful. The pickup sounds just like a PG in terms of e.q., but it hits the amp harder. Another difference is that PG+ were [oddly] only made as humbuckers, while the regular PG can be a humbucker or a Trembucker. Obviously, if you want a PG+, you'll have to buy it used from someone who has pulled it from a Fender guitar, and you don't really get to pick your color. You can buy the regular PG Trembucker off the shelf new, in any color Duncan make. I prefer the lower output PG in a Strat anyhow (matches the singles better IMO), so for me the choice would be clear: a regular PG Trembucker.
