Jake, your the second guy this week that wanted to dive into the deep end of the learning curve. Thank the Lord you don't want to use carbon fiber. Nonetheless, anything with Kevlar in it is a high dollar project. What you describe sounds like it has the potential to be kind of heavy. Why are you using mat? It has limited strength and will soak up a ton of expensive resin and increase weight. If you can't build it below 50 lb. it isn't worth using Kevlar. Are you aware that in most laminations the Kevlar is buried by gelcoat or a layer of 'glass so that abrazion (like sanding down a mistake) won't let Kevlar tuffs pop out? They're almost immpossible to get rid of.
Are you aware that Kevlar is not only a super fiber it is also super hard to cut. They sell special shears just for this purpose and they cost big bucks too.
I wish you luck but what you describe is not an entry level project. I'm the resident naysayer because I went down this road several years ago and am very glad I talked myself out of it. Boatbuilding should be fun or rewarding or both.
Charlie