Aaron, a suggestion (and this coming from someone who can't sew - so please take it with a grain of salt), if i were to attempt a DIY sewing project, any project, i would probably find a great product already out there (GG or BMW tarp, HS tarptent, etc), and copy it - and then, add any "tweaks" i think that i would need (e.g., attached bug netting to a GG SpinnShelter, etc.).
It would be nice if you could find an actual product and measure the dimensions to get it right. Lacking the ability to do that, it's amazing, i've read Posts where a person has actually contacted the owner of some of these fine Cottage Industries and the owners actually "gave away the store", so to speak, and told the person the acutal dimensions of each panel and how to sew it. Go figure?!!! These exemplary human beings are NOT in it solely for personal profit. Their love of all things outdoors and willingness to help another succeed, at their own expense, so to speak, still takes precedence over accumulating personal wealth - a fine example to us all.
Just a thought.