I have the hatching bug, so many questions. Any answers?

I just bought an eco 20, and I would like to hatch more than 24 eggs at a time so, I'm thinking of getting a Hovabator 1588. Any thoughts on the 1588? Also looking at getting the 3520 digital hygrometer for both the eco 20 and the 1588, has any one used this hygrometer and how do you like it. Also looking at the egg o meter for both bators to, has anyone used this and how do you like it. On the egg o meter, how does the sensor wire come out of the incubator, just under the cover? Or is there a hole that the wire feeds through?
If I did not get the turner for the 1588 and hatched in egg cartons, would rocking the bator side to side (sort of like the eco 20 does) about 6-8 times a day be turning the eggs often enough?
Thanks for any help
Bonnie