No matter which you get, our goal is for you to like it. I'd rather you get a single you liked than a double you didn't... So here's my short analysis...
A double costs $40 (and if you know about the process of making a double compared to a single, that's a bargain because they are more than twice as hard to make and they do take twice the material). A CCF pad costs $10. So, you're in for $50, period, for back warmth. One day, if you enjoy this hammocking thing, you will get an underquilt. When you do, you still can hang your double or you can get a single and the double with pad can be your loaner, for your wife, child, etc.
So there's the question... You have to have something. If you've only got a few outings, you can make do with a single and a squirmy pad until you get the UQ in the fall. But if you plan to be out a lot this spring and during the cooler part of the early summer before you get said underquilt, you might reconsider. $50 is cheaper than any underquilt I know of and squirmy pads in single layer hammocks thoroughly suck eggs. A double will also add to the WWM's durability, but it comes with a weight penalty.
So there you have it... if you plan to get an UQ soon, get the single and mosey over to another great cottage vendor for an underquilt when you're ready. If money's tight and the wife or significant other hates seeing charges on the bank statement for your gear, grab the double.
Now carrying the Mini Tattoo Stove!
Light weight. Low prices. Great gear.