Roger wears a 40s retro-style two-button double breasted suit with "8 buttons to show". That's a little wierd, since six buttons to show is pretty much all I've ever seen in a real suit. The buttons are what I'd assume are polished silver buttons (nobody in their right mind would wear bright white plastic buttons on a good black suit...however...we *do* know that Roger has horrible taste). I'd assume that for a real-life suit, you'd want to look around some fabric stores for silver buttons. The jacket has side vents and peak lapels...definitely a 40s style of lapel, although 40s style coats are usually unvented.
The tailoring of the jacket is form-fit at the waist. The jacket has no breast pocket...which deviates from reality a bit...you'll never find a suit without a breast pocket for a pocket silk.
I think the suit kind of looks like #12 on this page I found:
http://www.tomjames.com/custsuits/coatmodels.asp
The pants cut is a bit too narrow for a 40s style suit, more along the lines of a late 50s or 60s, when sharkskin suits became popular. Sharkskin isn't really shark skin, it's just a weave of wool that has a shimmery look to it, because they weave a slightly different color yarn into the warp of the weave. Wool gabardine also has a nice sheen to it, although it's mostly due to the density of the weave.
The pants are a little incongruous with the jacket, as well as his braces (suspenders). In the 50s, suit pants became narrower and baggy pants went out of style...narrower pants don't require braces to hold them up as they're fit to the waist. A belt works just fine for those.
Based on the highlights in the animation, I'd assume that the fabric of the suit was a dense-weave wool of some kind. Gabardine's a little too light but an italian wool would make for an excellent R. Smith suit.
You can probably dig around in vintage or second hand stores for a black double-breasted suit. You won't find something quite as expensive as italian wool, but you might find a reasonable likeness for less than $150...depending on the store, maybe as little as $20 or $50 bucks.
A visit to a tailor can get the waist on the coat taken in, and the pants altered to fit you accordingly. Bring good pictures with you, as that will help the tailor know what kind of look you're going for. Bring the silver buttons you find. Don't forget that he's got those same color buttons on the sleeves of his jacket, as well as for the braces on his pants. Depending on how much has to be done to the coat and pants...you're talking anywhere from $40 to $80 bucks to have the suit tailored to fit.
I'd suggest a simple white collar shirt. You can get decent ones at Mervyns or some other department store. If you don't want to go cheap, you can drop up to $200 bucks on a custom made shirt, but hey...if you can afford that kind of dough on a shirt, maybe you should be investing in constructing your own big O.
As far as Mr. Smith's tie is concerned, I'd assume that it's a black silk tie with a white print stripe. I'm not sure where where you'd get one. You can feasibly buy a black tie and have the white stripe screened onto it, but I'm not sure how one would go about it. I'd recommend against trying to sew a strip of white cloth down the center of the tie. It just looks so cheesy in those cosplay photos we've all seen.
As far as shoes, Mr. Smith wears a pointy-toed black shoe, kind of like these:
http://www.allenedmonds.com/webapp/wcs/s...=1&occasion=189
or these:
http://www.allenedmonds.com/webapp/wcs/s...=1&occasion=189
Of course, you don't have to drop that much money on a pointy-toed pair of shoes. You can probably find a similar pair for much cheaper.
Oh, and I almost forgot...black gloves. You want to drop a little coin on those. They usually carry the form-fitting kind that are popular with assassins at haberdasheries and gentlemen's clothing stores. I know of a store here in SF that has them, but they're about $60 bucks for a pair.
All in all, you'll probably drop as little as $250 to get a good ensemble together. If you're patient and really dig around for the right suit, you don't have to spend it all at once, just slowly gather up all the pieces until you finally have it all together.