Nothing The B motor wont handle the R's needed to run that quick, also its not to streetable. Now on the other hand if your talking about 1/8 mile you got a good shot at the 600 supersports with just 90 HP &95-100 ftlb tq. Thats a can do for street & B motors.
for the money you'd spend on a 103 use it and buy a 1000 Gixxer, take the MSF experienced rider's course and take in a track day or two and get it on. I tried the stroker route a few years ago, they're fast, fun..not cheap and a stock superbike will eat it alive..this time I got smart, I got the basically stock..[ hi/flo air cleaner, flashed chip and pro pipe] big twin and used the hop up dollars for a Ducati instead.
Dont worry about the fast factor. If it is that important, beef up your ignition system, intake system and throw on some drag pipes without the baffles, you will scare the hell out of any one near you. Stick with the Harley it has cool factor. Besides, chicks dig Harleys....
Only way to beat em is to join em, buy the new Ducati 999 and make em drool if thats the group you want to be with. Its about the only crotch rocket that holds any value, well that or an Aprilla seems to do alright.