I personally like a side-entry, so I don't pitch in A-frame style.
I pitch in modified half-mid style, so I like a 9' long and 6' wide tarp.
However, this is still open on one side, so you must pitch the opening on the lee side of the wind, or you're going to get wet in the rain.
The only two ways to get full protection in tarping is to get a very large tarp, or use a shaped tarp.
If I were getting something from ZPacks, it would be a Hexamid Solo. Same weight, better coverage.