It is important to know what application a component group was designed for because price is not the only consideration. Durace is designed for racing road bikes and focus is on weight and not durability. So Durace generally not a good choice for touring bikes because it not durable enough. People who race well enough to buy Durace are generally superb athletes, so you are not going to find gearing appropriate for touring either. There is one and only one exception to Durace not belonging on touring bikes, Shimano in their quest to maximize income, puts a Durace sticker on a barcon shifter. Components from other vendors racing groups are limited as Durace, and that includes XTR.
I do not believe that there is a touring specific group. Shimano at one time had a trecking group but it did not seem to be a good match for touring.
I will continue to stick with Shimano components, but similarities exist for Cane Creek, SRAM, etc.
Feel free to choose from road (Tiagra, 105, Ultegra) and mountain (Deore, LX, XT) groups to get what you want. Buy the best group you can afford, just remember that weight that rotates is more important that weight that does not. The importance of rotating weight is amplified by the radius it rotates on. So in a hub, durability is more important than weight. In a rim, durability and weight are important.