University metalshop / makerlab - metric or imperial?
The decision will be decided based on where, or in what, you think the resulting parts will be used. Since you are in the US, going for the imperial would make most sense.If you start machining metric based parts you will soon find that you may have problems adding off the shelf parts. I think the sound way forward is to figure out if you will depend on parts from elsewhere and to what extent these will likely be metric or imperial. Being able to switch will solve some issues but as you state, if there are mechanical differences in the machinery, you may end up with less accurate parts when switching to whatever system the machinery was not made for.