Umm, I personally am against the .22lr conversion. That's $250 worth of ammo that you could use to get used to the kick of a larger round.
Glocks are excellent weapons and I carry a G36 in .45 ACP. I would not go with the P99. I've fired one in .40 S&W and the trigger pull was weird. One of those first shot requires a longer pull trigger things. Of the others you listed, I'd suggest a P226. Excellent quality firearms. They cost about as much as a new M9, but spare parts and extra magazines are much more expensive compared to the M9 (that's why the government issued the M9 instead of the P226 to troops. Special Forces use the P226 though).