#1
Of course these are overdone, but I am afraid I can't look to anyone else for advice.

I need a new guitar to suit my new style - light rock, blues, and jazz.

I was thinking
do I get an American Stratocaster?
or
do I get a Standard Strat, and add my own things?

I realize, if I do get the American strat, I won't have construction problems and such... and it comes with a case, and everything....

BUT
I thought I wanted a different set of pickups - I wanted the Fender Hot Rod pups (I dunno - thats the name I remember)... and I wanted to add Schaller locking tuners, and LSR roller nut. (Of course, If I tried to add these things onto the American, I wouldn't have enough money...)

In summary:
An American Stratocaster

or

A Standard MIM Stratocaster with the following upgrades
Schaller Locking tuners
LSR Roller nut
Fender Hot pups
and Fender American tremolo system.

The thing is - the second option is only about a 100 dollars less than just getting the american.

I dunno. advice on these things please. Persuade me from buying or not buying the upgrades - are they really helpful, is the american tremolo any better than "synchronized" ones that come standard on the Mexican strats...? etc...
#2
For what you want, including the jazz, get yourself either a used MIA G&L Legacy or a new Tribute G&L. The PTB (passive treble/bass) system will come in very handy for jazz tones, they are MUCH better build quality than the corresponding Fenders, and have infinitely more of Leo's heart in them.
#3
Id go with the G&L, or maybe a good ES-335-style guitar. very different tones than the single-coils, but still get some nice jazz sounds and great blues sounds from it.