converting dirtbike into sumo

I was just curious about how much it would take to convert a dirtbike into street legal.

Things i know you have to have :
lights
tail light
speedo
battery
kick stand

Things im not sure on
small alternator?
turn signals?
starter?
ignition?

I wasnt sure if exactly how much this stuff is but making a rough estimate the normal stuff that people get to make it into a sumo. Or i wasnt sure, if i get like 250 or 450 if i would have to much fun off road and not bothering to make street legal. id like something to ride around town and be able to take for rides, the only thing is the type of riding that i would be doing if it were there was alot of highway or just around town or turns. im pretty sure they top out at like 80+ depending on the sprocket set up, and mabey 55-65 would be a more confortable speed with out beating on the bike to long.