short and low hammock

I am new to hammocking. I discovered I needed a hammock when I was showing some homeless guys how to be more comfortable. So a tree covered hillside with out a flat spot to sleep made me think hammock.
My tarp shelters are low and all closed in tight to the ground. I want to stick with the same tarp pitch so I want to go short and low with the hammock.

Tell me what is wrong with my ideas.
I was going to make a hammock out of my bivy which has hoops over the head end. I strung it up and can see I am going to need to sew on lots more suspension straps and spreader bars.

So maybe I will make a hammock to put my biy on. I propose to take a 30"x 90" piece of sturdy material and sew pockets on each end to insert a strong stick in each.
I will tie head end and foot end sticks in the middle to vertical tent poles in my shelter head and foot. Then find a tree opposite each end to tie a line to and put the correct amount of tension for a hammock.
I hope the spreader stick at the head end will keep the hammock almost flat for the hooped head enclosure of my bivy.