What are some good brands to look at besides Stoeger? It would be for upland bird hunting and I'd like to stay less than $800. What does everybody think?
Unless you come across a used one, the Yildiz or the CZ won't be available inside the price point indicated. The advantage is that both models have scaled frames that equates to aspects such as good balance/handling etc. Those qualities will be important if the intent is purely wingshooting.
The Yildiz is equipped with single trigger and screw-in choke tubes. Doubles triggers (read Bobwhite model), fixed chokes on the later. Personally, I found the overall construction (more traditional design) of the CZ to be much better.
Another option within budget (and it's a good option, nevertheless) may be to look for a new/used Baikal IZH-43 (presently known as MP-43) or the now discontinued Remington SPR 210 (which is the same IZH-43 that wore the Rem brand for a while).
The Baikal .410 shotgun although well built will be heavier (aprox 7lbs) and on a 20ga frame (how to tell - the distance between centres of the firing pin holes will measure 25mm). The firearm will lack the end-to-end finish and much of the handling qualities (should one care strictly about such things) when compared to the Turkish makes for example. The breech resembles that of a double rifle.

Admittedly, I do own a Baikal (in 28ga though) among other brands and it doesn't bother me.
http://www.remington.com/en/products/archived/shotguns/side-by-side/spr210-side-by-side.aspx
I must add - the shotgun, regardless of make, will have to fit.