I am going to be buying a glock 17 and was wanting to know what factory night site options there are out there. If there are choices which one should I get. Are they threaded on or stacked on (which is better). I would like to get one that has fixed night sites (is this possible?). It would be really cool if I could get two different colors (front site one color rear site another color). How long do night sites last. Thanks for your input.

My choice would be Heinie Slant Pro sights.  

G

OK are these sites ones that come from the factory that are already on the gun?

The front sight for a Glock will be attached via a 3/16 screw (you need either a thin-walled socket, or a special sight tool for Glocks to install it), while the rear is installed with either a sight pusher, or  (as I did) simply tap it in using a nylon hammer. The factory front night sight is staked on, however. Meprolight offers different colored sights front & rear; wether or not other makers do also, I don't know. Here's what my Trijicons look like (NO, the front sight isn't crooked, and YES, I know the rear sight is drifted to the right). I have read comments that the Meprolight sights are a little brighter than the Trijicons, but can't speak from personal experience on this. Trijicon warranties their sights for 12 years.

You need to pick the front sight out of the 3 dots though

This is a pretty good point, I have to admit.

Quoted: The front sight for a Glock will be attached via a 3/16 screw (you need either a thin-walled socket, or a special sight tool for Glocks to install it), while the rear is installed with either a sight pusher, or  (as I did) simply tap it in using a nylon hammer.

I used a sight tool for Glocks that I got at Brownell's.  It's a bit for the magnatip screwdriver set, but it will fit in a Black and Decker or any other common replacable tip screwdriver.

I used the sight pusher on the rear sight like you did.

I put Mepros on my G19.  I like them alot.  They are very bright, have an equal or better warranty than Trijicon, and they cost less.

My front sight dot is green, and my rear sight dots are yellow.  Green is the brightest color on a night site.