Actually you really don't need a 100+ for a single frontosa. A typical sized 60 gallon tank of 36"x18" is just fine for him to grow into. It's a bit of a misconception, Fronts generally require huge tanks because they are colony breeders - unless kept singly they need to be kept in groups of one male per several females, sometimes with an extra male to take some of the aggression of the dominent male. Now put together half a dozen of these fish and you can see why giant tanks become necessary.
What it comes down to is that I don't see the point of keeping these fish unless a colony is kept - a single Frontosa floating in a tank is pretty boring. If you are happy with this type of tank though, this is something to keep in mind.