Lettuce will start bolting when it gets hot, but you could follow them with a different type of leafy green like chard, bok choi, or kale that’s more heat tolerant. (Bok choi will eventually bolt too, but I generally harvest the whole plant before it gets to that point.)
If you have a county extension service through your state’s land grant university, they often have great resources and suggestions on what varieties grow well in your area. They’ll also have suggestions for when to plant as well.
My favorite indeterminate tomato is Balck from Tula. Great flavor, and more productive than Brandywine in my experience.