[Billla]

Bottom line is that if you don't have the tools and experience you'll spend far more trying to do this at home than handing it off to a good shop...and when you're done you still have iron guides. Good reamer sets have a guide that fits into a 60 degree valve seat to ensure the guide is concentric with the seat...and they sell for about $200.

This is one of those things where if you're only building 1 or 2 engines it's just not worth the investment. Doesn't mean you can't do it at home, but you need to invest in the right tools and the time to learn the skills.