I had this problem in the rented condo where I used to live, and I was the one doing the flushing!
Perhaps others will chime in, but since I bought a new toilet for my recently purchased house (an American Standard Cadet 3) I notice that I get more flushes out of it before it overflows on the rare occurance that it blocks. The old one in the condo would overflow with the first flush after the blocked flush. I get about two/three out of the Cadet 3, by which time I stop and get the plunger. But it has not spilled on the floor yet, unlike the one in the Condo. And if it did there would be less water on the floor....hopefully.
So what I am saying is that I have not seen a toilet that will prevent overflow but the newer, smaller capacity toilets (I would guess of any brand) will take a little bit more flushing to overflow when blocked than the old larger tank models.
Alternatively you could install a toilet that blocks less easily (again my Cadet 3 is good) or change his toilet paper. I have awful problems with Charmin, even on my new toilet, and any brand that feels cottony or soft is a bad idea. Thin, 1000 sheet rolls are the best.
You could also try a Floodstop valve but this could cause you more trouble than it is worth through false alarms (I removed mine because of them). This electronic valve will shut-off the water to the toilet when it senses a wet floor. So if he is flushing an already overflowed toilet, this will stop him. But think carefully before taking this route. It will not stop the toilet overflowing in the first place and because they are prone to false alarms you may need to teach him how to reset it (and my grandmother cannot even operate a microwave).