disc brake/drop spindle kit..all a direct bolt on?

[oldblue1968chevy]

Looking at buying front disc brakes and drop spindle kit from a fellow member....he wants 500$+shipping....is this a fair price, or should i keep shopping? Is everything there i need? or will i have to get new balljoints, tie rod ends, tie rods, or anything else?? really like to convert my drums to disc and lower a bit too while im at it...not really sure if its worth his asking price of 500. i hope this is not against the rules for me asking this type of ? if its illegal mod. delete this or i will.....

thanks!