I have seen these used by many USNA midshipmen - I would think wording could be adjusted, as well as seals. Herff Jones doesn’t miss a bet when it comes to all things collegiate + class year + school crest.
http://www.navyonline.com/ePOS/form=robots/catalog.html&this_category=196&store=460
And, since it’s not an official military entity doing the inviting, but a personal invitation/announcement from family, then there is no prescribed format, although you want to get the basics right. I have also seen very “artsy” invitations and announcements for USNA mids.
I am sure ROTC follows a similar path. It’s personal. There are enough examples out there to get a feel for the phrasing for graduation and commissioning, plus adding in service seal and college seal.
Be sure you know if the commission is “USX” or “USXR.” As in, Dudley J. Doright, Ensign, USN or USNR.