Bell Peppers in the heat!

I've never been able to successfully grow Bell Peppers in the hot Texas heat. Most other varieties do well and produce well, but my Bell peppers simply wilt when the real summer heat arrives. This year, I will try growing them in 25 gallon containers instead of in the soil and see if more moisture and a shade cloth will make a difference. I'm curious if anyone can suggest a variety of bell pepper which may withstand the heat better than other varieties.

In the past, I've had good success with some varieties of long chile peppers like Numex Big Jim, Giant Jalapenos, Habaneros, and a few others. Unlike tomatoes, I don't know variety traits very well because I have been limited to growing varieties vendors sell. I will try growing from seed again so variety suggestions will be appreciated.

Also, I know the best tomato seed vendors having dealt with them for many years. Please name some pepper seed vendors whose variety descriptions seem most accurate.

Thanks

Ted