Use a short noodle that has texture so the sauce "clings" to it more. You can use traditional pasta, chickpea, gluten free, or other pasta alternatives too.
Mac and cheese is incredibly versatile with flavor add in's. I like poblano pepper, roasted garlic, green chiles and a lot of smoky paprika when I make mine on the smoker.
Combine the cooked pasta and the cheese sauce. A little heavier on the sauce helps as the pasta absorbs some of the liquid as it cooks. Mix in your poblanos and green chiles here as well.