Even though there are many excellent gunsmiths, that doesn't mean they will work on your XD. A couple of years ago, I took my XD40 to a well established (20years) experienced gunsmith and he returned my XD saying he was afraid he'd damage the slide as the sights were on so tight and his sight installer tool would not fit on the XD (the XD uses a very wide sight on the rear; if you have a sig sight tool, and a standard XD if you file the rear to make it more narrow, you can get the Sig sight installer to work, but of course, you mutillate the rear sight in so doing).
I believe Trijicon will install your sight for a nominal charge and I'm sure you can send your slide into Canyon Creek or contact Ajamesp51 to have this done. (or for that matter, Springfield)
If you send your slide in, make sure your present factory sights are well regulated. If they are, tell the smith to install the new sight centered the same way to the witness marks.
As for just having the front night sight; this has in fact been a common configuration for the Navy SEALs on their Sig 226. Close up, you just look at the front sight and align with the center of mass....
In my experience with my XD40, I replaced the factory sights with Trijicon night sights and found the POI was now at POA which I prefer (instead of the 6 O clock which the factory strives for)