I'll second that HG will custom build any tarp you ask for. Just fire off an email and they'll build whatever you like. I haven't bought anything from Zpacks yet (...but boy does that Blast pack look sweet), but I have spent a lot of money at HG and have always been impressed with the work - naturally, when I decided to pull the trigger on a Cuben tarp, I turned to Adam. Now, I'm waiting on 2/3 sided Cuben tarp with custom tieouts. Since you now know that you can get the same material from either company, I'd suggest deciding exactly what you want in a tarp and asking around to see who will do it for what cost.