Something special to surprise my boyfriend with?

My boyfriend finishes his TAFE course in architectural drafting next week and has spent the last 6 months working his butt off on this assignment that is going to be presented to industry reps at the end of June (in hopes that he will be offered a job). He has really turned the course around – he almost failed his first semester but has spent the 2 years since really working hard and is now one of the top in the class. Because he has been working so hard (including a lot of 3am bedtimes) we haven’t been able to spend a whole lot of time together lately (especially as I only finished my second last semester of university 2 weeks ago – I was flat out with assignments before then too). I wanted to do something nice after next week to surprise him and congratulate him on finishing and all the hard work he’s put in, but I don’t just want to buy him something tacky. I thought I could take him away for a few days, but we’re doing that for our anniversary in a month (we do it every anniversary) so I don’t really want to take away from our anniversary. Maybe I could take him out to dinner? Is there anything else that could go with that? How would I be able to surprise him with this?