I've had the Wilkinson bridge on for a year now and found it a little easier to set the intonation. I have a friend that actually fine tunes my guitars for me, I can get it to 90% but he gets it spot on, he thought it was a pretty decent bridge.
With regards to cost of a partsocaster or a Strat for that matter, it is a little higher than most would expect BUT you are putting together a guitar that suits you. Even if you bought a used MIM or MIA you would probably want to swap pickups at the very least. For myself, I wanted a maple neck with vintage tint, an ash body, noiseless pickups, vintage looks, and light weight. Around here I couldn't find such a guitar at a reasonable cost. 9 out of 10 American Tele's I've seen come through the store are boat anchors and to buy a MIM and upgrade the pickups, and bridge you are getting close to my build price and still have the pale looking neck and a fairly heavy guitar. The best guitar that I found was a 52 RI. The weight on the one that I found was about 8 lbs, the finish, neck, pickups and weight were spot on but the price was $1899 plus tax. A great guitar but too pricey for an amateur. So when I sat down and added up the cost of the parts to get me close to this guitar I found it could be done for half the price.