Ah, the Bandit 1200S, I would ride the hell out of one of those. Sort of the logical extension of my bike, the yamaha FZ6, but with a ton of torque. That's a great mile eater, and the price is incredible. Dale's old GS500E was a great practical bike, and great way to learn.
My whip:

2007 FZ6, bought it new, put bags and seat and bigger windshield on it, now has over 47k on it. These last few years I've put 10-12k on it annually, about 2 hours a day for 5 days a week for 9 months of the year, 100 degrees F down to 22 F. But look at this thing... this is not what Dale wants. This is ugly, pointy, and practical. This is a price point. This is a math equation. This is a bike for people who want to rely on a motorcycle to get a paycheck for years in a row, with no garage to do work in. I don't look at my bike and get all moist, I just see it as a more fun way to get my shit done.
Now the Speed Master is a great bike, you would not be disappointed. They look good stock, and you can do a LOT with just a new handlebar and mirrors. That shit bolts on with allen wrenches in minutes. The motor is enough to happily cruise all day at 75, the bike isn't so big and clunky that it's a pig to muscle around through parking lots. A guy at work has one, so I get to see it up close all the time.
For inspiration, you need to know about a few sites if you don't already. First is
Bike Exif (
http://www.bikeexif.com) out of Australia. They have something new every day, they cover all major styles, and the guy's got a good eye. Great place to get a sense of what you do and don't like. Shit like this is all over it:

Second, there's a french guy living in Africa who posts a blog called
Mot Art, which is an odd blend of equal parts fashion, motorcycles (your kind, I think, the classics), african models, architecture, and boats. Somehow it works. Befriend him on Facebook if you like what you see, he's a nice guy.
http://www.themotart-journal.com/ and on FB his name is Frank Charriaut. I strongly, strongly predict that will LOVE this guy's stuff. He's basically you with longer hair and an accent.
And finally my opinion on Sportsters... the 883 makes 45 hp. Your GS500E made 52 at the crank. So the 883 motor is almost exactly as much power as that GS, but with 100 extra pounds, worse brakes, way worse suspension, less ground clearance, much more expensive parts, and it costs 2x as much. But it looks good.The 883 is known as the "chick" harley, which is somewhat unfair, but only
somewhat. It's probably 85% mechanically the same as it was when it came out in 1958 - they've rubber-mounted the motor now and it's fuel injected, but the bones are the same - and that carries some pluses and minuses.
On the plus side, it looks classic because it is a classic. It will never be outdated. Evel fucking Knievel rode a sportster (though it wasn't no damned stock 883). It is somewhat affordable for a harley, and if you have been infected with Harleyitis (you may not be) then nothing else will cut it.
On the down side, it handles and performs preeeeetty much like a bike from the late 50's (suspension and brakes are better but nothing in the same universe as modern performance bikes), and it sucks to pay a 30% markup premium and get that in return. It won't do highway miles very happily. It will impress chicks but not bike people -- they will all know it for what it is (the "chick" harley)... that may or may not matter to you.
In conclusion: I think you can do better. That Iron Sportster is manufactured "cool." Take a speedmaster or a bonnie black or a
thruxton, do some research, buy a couple of good parts (bars, mirrors, pipes) and make it something gorgeous.