Valve cover gaskets

I'm going to replace the L&R valve cover gaskets(actually Frt and Rr) and was wondering if that since there is SOOOOOOOO much involved would it be feasable to just take the heads off and do valves and guides at the same time? Do you really need to replace the head bolts when you remove the heads? I do have some bluish grey smoke when I start the motor on the 1st start of the day after it sits for a while. ( I suspect that the umbrella seals are toast) But since I am going to do a top takeoff for the gaskets , I figure I should do a valve guide/umbrella check and a valve job too. Any suggestions?? Thanks Rick :1zhelp: