I would say buy a Canon. Why? Canon has a longer flange-to-film distance than Nikon does, and so there is plenty of room for lens adapters between the lens flange, and the back end of lenses made by seven different 35mm lens makers. The Canon EOS system can use lenses that were originally made for M42 thread mount cameras, Nikon, Olympus, Pentax K-mount, Leica R, etc.
Lens adapters from
eBay are around $17.99 each. FotoDIox makes a pretty good NEW, Nikon G-series lens to Canon EF mount adapter, which is expensive, at $129 or s, but it allows one to use Nikon G-series lenses, which have NO aperture control ring on the lenses; the Fotodiox adapter uses NIkon's 1959-era MECHANICAL aperture control mechanism to adjust the f/stop used by means of a simple,reliable mechanical adjustment tab that gives basically a 7-click f/stop adjustment range from wife-open to minimum f/stop.
If the school has loads of Canon gear, and YOU have a Canon, plus any NIkon gear you currently own, and a lens adapter or two, you'll have access to all types of stuff! And, if you are going to learn commercial photography, learning how to focus a lens stopped down,and shot from a tripod, will be a very valuable skill that you absolutely MUST learn to do.
I honestly think a Canon 5D classic would be better than a 60D, unless you need video capability...