I would avoid the guide rod lasers. Ive SEEN one break and the slide fly off the gun.

Personally, I dont care for lasers on a pistol. Or any gun for that mater. If you sight them in at a certain distance (say 10 yards) and any other distance it will be WAYYY off because of the angle of the laser. I had a green laser on one of my ARs and sighted it in for 50 yards. At 100 yards it was almost a foot off.

The only type of laser I would use would be the Crimson trace grips.

As far as the offset affecting your aim, it seems like you could put the laser and the bore parallel and have it sighted in so that the bullet would always hit something like 1 inch to the top left of the laser.