For a hobby or small commercial shop go with a 240v center tapped delta
service. You get 240 three phase and 240/120 single phase all out of
one panel. Yes, you'll end up with a few unused slots in the panel due
to the 'high leg', but who cares. If it's a mystery as to which phases
supply which voltages to neutral don't even take the panel cover screws
out and leave it to someone who knows, but it's really no big deal. The
power company, at least around here, prefers this service as it
generally has a lower installed cost, they can get by with just two
transformers and wire it open delta. To you, the end user, it generally
won't matter. You'll have extra work to due for single voltage 480V
motors, but most machine tool motors are of the dual voltage variety
anyway. I'm hard pressed for a valid reason to even consider another
service for a small shop.

You dont' mention if this is an additional service or a replacement
service. I had three phase installed a few years ago. It was a
replacement service. I went with 240V center tapped delta. It's the
way to go in my opionion. It will maintain all of your single phase
service with no(minimal) changes. You will gain "true" three phase.
Yes, there is a wild leg that needs to be kept in mind when considering
single phase loads. It's not really a big deal.

Check with your power provider. They will have a PE on staff that can
answer any questions. They can tell you what they will do, and what
expense it may be to you. Going to 240V 3ph cost me nothing for
installation. 208 or 480 would have been a minimal fee, but would
have required other "local" infrastructure changes to accomodate.

As many have suggested, stay away from 480V power. It steps things up
to a realm where you NEED to know exactly what you are doing or you
will hurt/kill yourself/others. It will also increase the expense of
equipment/materials. Everything will need to be 600V rated.

JW