Yeah, get a 1911 Sig, 'cause everyone needs a 1911 that even the 1911 experts don't recomend, and that come with safeties that can allow the hammer to drop without the gun actually firing.
But seriously folks, if you're looking at reloading over the long term (which you probably should) 40 brass is amazingly plentiful and dirt cheap (frequently free, if your range hosts the local PD quals) and brass is normally the most expensive part of the equation. 45 brass is expensive, but it does last. Also as mentioned if you decide you want your Glock in 9mm flavour, your conversion is easy and cheap. I'd go with Gen4 - in either M22 or M23 (the 23 is probably the best Glock made IMHO)