I think the two most common knits you’ll be dealing with for a project like this are going to be jersey knit and interlock knit. Jersey is more commonly used in tshirts, as it’s lightweight but it tends to be thinner than interlock fabric and, I think harder to work with. Jersey tends to get roll-y and that drives me crazy. While Interlock knit is thicker than jersey, it’s actually pretty nice to cut and sew with. If you want something that’s similar to your current dress, it sounds like you should look at interlock knit. Please post a pic when you finish and good luck! 🙂