I was messing around with my taurus trainer and for the first time got my sights inline so I figured I would put on some high vis night sites is their anything to look for  when ordering sights for a goverment slide with notches on the front and rear of the slide.

Yes. First thing to do, is to buy some "periods" for your posts.    

There are two different sizes for most 1911s on the rear sight cuts. I have NO clue what those two sizes are or why they're different, all I know is I see two sizes listed.

SGB or pulpsmack or someone will need to chime in on the where's & why's of that.    

In the meantime, a visit to Novak Sight's web site should get you on the right path, IMO.