Im thinking of picking up a 1911 but want a few features and can't find all of them in 1 gun. I want an aluminum framed officer with as close to a 4" rail (STI 3.0=3.96") as possible and chambered in 9mm. A CCO if you will with a rail. i love the Duty One 4.0 Lite but not sure if I can conceal it. How much harder is a full size frame to conceal then a Glock 19, what I carry now? Really don't want to go taller than 5" in height.
Any help for a rookie 1911 enthusiast?

I CCW the 4.0 Tactical SS.  The 19 isn't much smaller than your 4" Duty one, shrug.

Why not get the 2011 Tactical 3.0?  Aluminum frame, same weight as your 4.0 Duty One, but hi-cap.  Just standard grip size.

I think you are looking for something similar to a Springfield LW Champion Operator

Outside of that, for something I'd buy, probably the WC CQB ultralight (4in) which will be a bit shorter than the 4.26bbl Tactical STI and 4.37in Duty One 4in ers.

http://wilsoncombat.com/new/handgun-cqb-lightrail-lightweight-compact.asp#.VI-gTyvF9KI

n00g7-I live in a commy state-CT. So unless they make 10 rd mags the tactical is a NOGO. Also, havent seen any around to check out the grip width. AKHappy- I edited my post. Looks perfect except I might stay with 9mm for cost of training and lack of room to collect another caliber.
If I cant find one I might suck up the size and go with the Duty One lite 4.0 or skip the rail and get a DW CCO but still searching.

Thanks for the help so far guys.

Yes, there are 10 rounds mags.  45ACP in the flush fit is 11 rounds so you're losing one round.  In 9mm you lose 7 and in .40 lose 4.  

If you're GTG on a 1911, you're GTG on a 2011.  My 2011 SVI is similar to a 1911 with slim grips, STI pretty comparable to standard size 1911.  

Grip width, measured side-to-side, approximately halfway up (at the STI logo):
STI: 1.28"
TRP: 1.31"

Grip measured front-to-back, perpendicular to the mainspring housing, just below the grip safety:
STI: 2.07"
TRP: 2.02"

Grip circumference, measured by wrapping a string just below the grip safety:
STI: 5 11/16"
TRP: 5 3/8"

Trigger reach, shortest distance from surface of grip safety to trigger face:
STI: 2.725"
TRP: 2.80"

Also, here: http://forums.1911forum.com/showthread.php?t=376918

Thanks!! (like I needed more options, lol ) Back to their website I go, lol.

Have you considered an STI Elektra? There's no rail but they are designed specifically for concealed carry.  Lightweight forged aluminum officer length frame, Trijicon tritium Heinie two dot sights, fantastic trigger, extremely good accuracy from it's match barrel, full carry melt treatment, factory Cerakote finish.  The barrel is 3.24" instead of 4" but that makes it easier to conceal and the accuracy is amazing.  I've had mine for a few years now and love it more now than ever, although mines a .45acp.  It comes in more colors than pink like mine, there's also purple, blue, red and black, with the black looking amazing in my opinion.  If I could afford another, I'd probably carry two of them lol.

Brandi, no I havent. I want a longer sight radius and a rail. Thanks though. I'm considering a Duty One lite 4.0 or a Tactical SS 3 or 4.0.

I don't think you can go wrong with the 4.0... I have two (2nd has night sights).  Carry in INCOG IWB R-Hand holster on the side or L-Hand holster behind the back depending on what I'm doing.  They are ridiculously accurate, consistently shoot 4" targets from the holster at ~35 yards.

Very nice! A gave an INCOG a try with my Glock 19 and it dug into my boney azz hip at 3 o'clock. Lol. For IWB I prefer a hybrid but at least I know what my options are. Thanks a lot. I'm only leaning towards the Duty one 4.0 lite because it's lighter but damn the SS is nice. Been searching for a used one in good shape. I'm gonna buy one of them in a week or so. lol.