Although I can't open the sight I have a few questions. What is it you're trying to do? Improve upon project posted here or start from scratch?

What is the range of temperature you want to display?

What displays do you want to use? If flickering is a problem you could use a faster update rate but the display will only be as good as the quality of the display. I agree 7 segment LEDs are a dime a dozen but some are better than others. Although if you want large displays you may not be able to update them but will need to turn them on the whole time using FETs or transistors.

What is it ultimately you'd like to see from this project?