DO NOT TAKE YOUR GUN TO GANDER unless you have the parts and they have the time right then and there. I have seen horror stories of folks not getting their guns back for months for simple work. You want a good gunsmith, you are going to have to look for em.
Does your CZ have a roll pinned front sight or a dovetailed front sight? Realistically, if a local gunshop has a sight press (or you can get one), its an easy situation. My old CZ I installed night sights on before selling her. Easy stuff. Drift of the rear, install rear, carefully due to the tritinum vials. The front sight was roll pinned on. Drift (carefully) roll pin out, off with old sight, on with new sight, for a damn good fit, use a NEW pin.
All of this is easy stuff for a properly outfitted gunshop, realistically. If push comes to shove, send it off to the night sight manufacturer (Trijicon or Meprolite or whoever). They should have it turned around fast and most of the time just need the slide (no FFL needed). Gander is not the answer unless they can do it right there in front of you.