Machine Head or not

Ok well I finally got the valves adjusted and noticed the engine shaking after buttoning everything up. It had before as well but there were some issues the carb had a crack in it once that was found I assumed it was a vacuum leak screwing with the fuel to air ratio at idle.

I brought it to my mechanic turns out the valve guides are worn out mostly on the exhaust side. On 2 or 3 the play is around 5-6 mm. So my question is should I have head machined and new guides installed or should I replace the head. I have looked around for a head and I am not having a lot of luck but I haven't looked to hard. As for the machining I called 1 person and he quoted me around 250.00. I don't know but hope it includes disassemble and reassemble. Does having new guides installed introduce anything I should know about?