Backyard Aquaponics
A place to discuss aquaponics

There are couple of local hatcheries near me, one sells bullhead catfish, yellow perch, bluegill, and trout while the other hatchery sells tilapia fingerlings. Where I live we have cold winters and relatively warm summer months.
At first I was thinking of going with something like 10 bullheads, 20 yellow perch, and 20 bluegill all in the same tank. From what ive read it seems like those types would be able to get through the winter with a heater just to keep a hole in the ice.

I was also thinking that it might be good to start out with tilapia and raise them through spring, summer and early fall. That would be a little more than 6 months for them to grow to an edible size. If they bred which Im sure they would, I could keep some fry in a fish tank during the winter and put them into the large tank the next spring to use for my next generation. During the winter I would use a heater to keep a hole in the ice and maybe I could put some rainbow trout in. That would be 6 months for the trout fingerlings to grow to an edible size before the tilapia went in when spring comes.
So, what sounds like a better option, trout in the winter and tilapia in the summer or going with a mix or species year round?

I would go with the mix. I don't think your climate is warm enough for the Tilapia without adding lots of heat.

Yeah, agreed - stick with the cooler weather fish. I'm not overly familiar with your species, except the trout, but you will need to keep compatability issues in mind.

Rainbow trout can be quite an aggressive fish and, while there are exceptions, are generally not good mised in with other species.

If the yellow perch are anything like their close relative the Eurasian perch, you'll find that they are aggressive to other species as well.

i have yellow perch and bluegill, they're fine together, hoping to try trout later this year..

i think once the catfish got bigger, they'd eat the perch and bg

tilapia would be way to difficult for me due to the temps they like, but i've thought about trying a "short season" for tilapia.. let us know what and how you do!