I personally haven't heard of STI 1911s. I suggested a Kimber, Smith&Wesson, SIG, or Springfield personally. My dad also wants to get him a SIG 1911.
i put STI above all the others you listed. even the spartan V is amazing. you won't need to upgrade the sights, because the ones that come on it are top notch. sig is still ironing out the bugs in its 1911 line. the gsr line was terrible. the new ones are better, but they just haven't been doing it long enough. then you have people like kimber who have been doing it for ages, and get it worse every time they do a redesign.