If it comes to that, the really cool replacement is a remote reservoir under the tank so all you see is levers. BMWs run that kind of setup stock, and it makes for a really clean handlebar area...
Our bikes use the same front caliper as the same year's XS650, so go to http://www.xs650direct.com and punch in item Part #29-0016. $18.95 Canadian.
I just checked - doesn't the Heritage Special have a drum brake in front?
In which case, no.