You can get lots of different 1911s in 9mm.. so if you really want one, get one. They're good guns.
I don't like the idea of owning the same guns with different caliber. I like some variety and since I'll eventually get a 1911, mind as well get an all metal frame 9mm now. I've also read that you have issues with a 9mm 1911 if you use anything less than a 124gr round.
Nice rig for your bike, too. Not sure if I'd wanna display my guns so prominently for all to see, but if that's your mode of transportation why not.
Ehh, this is a legitimate hobby and we shouldn't feel like we need to sneak around to get to the gun range. I've gone beyond what the Firearm Act requires to transport NR and R firearms with 3 different "levels" of locks. One padlock to remove the case from the bike, 4 padlocks on the case itself, and a cable lock on each firearm AND a Firearms Act placed inside the case in-case I get pulled over by an overzealous cop. The benefits of course are saving $10 per trip due to gas saving and you get to ride the bike more often! haha.