I don't have a HovaBator, but I do have a poultry incubator... It's the Little Giant Model 9200 Still Air Incubator.. To get an idea of its size in comparison with the Hovabator, it says the approx. capacity without automatic egg turner is 46 chicken, 118 quail, 90 pheasant, or 40 turkey or duck eggs. I really need to get a tape measure. Lol
I use small food containers for my corn eggs--probably 4x4x4 in. (couldn't give you the exact measurements), and 4 of them would fit comfortably in the Little Giant--maybe 6, if you didn't mind a really snug fit. I have two in there now, each holding about half of my 17-egg clutch... Approx. 8-9 eggs each. You could easily fit eight 5- or 6-inch delis (stacked in twos) as long as none are taller than 2 1/2 inches (anything taller than 5 in touches the heating element).. You might even be able to fit eight 8-inch delis--or at least 4 on the bottom with smaller delis stacked on top. In other words, at least 80 corn eggs if you stock your delis right. Again, though, I don't know if the Little Giant and HovaBator are the same size, so it's possible the HovaBator can't fit as many or could fit more than that.
If you plan on ever having more than 3 or 4 clutches at once, you might be much better suited to go for the cooler idea--you can make those as big as you want! Otherwise, I remember seeing a
good deal on an incubator, incubation medium, and delis on LLLReptile that you might want to check out.
I hope all goes well with your gravid girls, and congrats on the imminent eggs! =)