I would go for the best and fastest support. Hardwarewise it seems that any middle-of-the-road PC would do. There should be no special requirements.
Being a business you can order (and pay for,of course) 3 years of next-day on site hardware repair with Dell, for example. If your local computer shop offers a 1-week bring-in repair for their custom-built PC the choice seems easy to me.
But if that local shop happens to be your neighbor and be ready to come as soon as you phone with a problem, that can't be beaten. If they offer support like installing and migrating your applications and setting up your backup scheme (and you don't feel up to that yourself), that would be a pro also.
Kees
we need a new computer for a medium sized optometric practice. what's the best way to go?, out of the box or one built by an independant computer consultant and why?

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