Matt - I'm not sure I understand you
First of all, Eric is right, $1,000 for an alternator? I got quoted $150 at my very reputable shop. Maybe it's the mechanic - he is after all the one who told you that "everything else needs to be replaced at 125k miles." And yes, I sure hope you don't have a vacuum pump on your 2.6, or you have even bigger problems then you could ever imagine.
Anyway, that's beside the point...
You seem to be complaining about fixing things BEFORE they even break. If you're so worried about being stranded by your fuel pump dying, then why not go ahead and replace it already? I know that it's expensive, but you seem to already have resigned yourself to the fact that you will need one in the very near future, so just bite the bullet. I guess I'm just trying to say, put your money where your mouth is - you're so sure you know EXACTLY what's going to break (on your 11 year old car, btw) so I recommend just fixing it.

Or else just sell the car to somebody who's not so paranoid about things breaking (especially things that AREN'T on your car, i.e. a vacuum pump?????) --> maybe time for a new mechanic Matt

pete