I can tell you what not to do. Layson's sells one that fits great. I got one several years ago, and it only worked for a few months. I have always had really good luck with stuff from Layson's, but not this time.
I can pretty much guarantee that the repop's being sold are all from the same manufacturer, whether sold by Layson's, Classic industries or whoever. And yeah, they're junk. Inaccurate, cheaply made, and not worth the $200 they charge for them.
