Some indoor ranges have guns for rent, but the selection is usually limited. My opinion is the .40 is just about as good as the .45. I personally like the .45, but that may be because I've got enough .45 reloading components to last me through a couple of wars.
I've got an FN .45 for sale if you're interested, just like new, factory box and all that came with it, including 3 14rd. mags. Re: concealment, I usually carry in the small of my back, in an inside-the-pants holster, opposite hand. I'm only about 165# but I can put that FN under a t-shirt and you won't see it unless you're looking real hard for it. e-mail me at
[email protected] if you're interested.