I decided I am going to purchase a XD9 Service for both CC and Target practice. These are the 4 versions I am considering and I really don't even know what a Slant Pro is. Also what version do you suggest for my intended uses?
XD9mm Black Trijicon Night Sights
XD9mm Heinie Tritium Slant Pro with Night Sights
Since you have decided to go with the 9mm version, just a suggestion, but you should consider going with the Sub-Compact instead of the Service model since you plan on carrying it as well. With the extended magazine that comes with the sub-compact, it's exactly the same as the Service model (*except for the slightly shorter barrel). This was, the sub-compact will make things easier on you for carrying.
I have a .45 Service and a 9mm Sub-Compact myself. Great guns!
I like the Service model, feels good in my hand. I have an XD45 in the Service model and my next purchase is an XD9 Service. I like the tru glo sights for my XD45, from now on they are going to be on all my pistols, I really like them. I don't think you can go wrong with any XD model.