Yes, they're available in all sorts of shoulder lengths and thread sizes on Ebay. For chucking reamers to get the holes round and the right size, try Victor Machinery Co. (www.victornet.com). On a lot of the standard shoulder bolt sizes, they have reamers .001" undersize, which will result in a very tight interference fit, almost a press fit. Once a shoulder bolt is installed that way, it's almost a solid as a hot riveted joint. It also helps to grind a slight taper on the end of the shoulder to help force its way into the tight hole.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!