Lenny - it looks like a call to CS is in order for a couple of reasons. First, the "Essentials" kit says you get blanks to turn, but the "Basic" (even though more expensive) doesn't.
A couple of comments on what you are seeing. The "Hot Stuff" glue is great. No two ways about it. The other product packaged with the Essentials kit may be good as well, I haven't used it. I have used a lot of Hot Stuff, from water thin to near gel. It isn't cheap, either.
As far as the double mandrel business goes, I think it is the same mandrel in both kits. They are usually called double mandrels since it is long enough to turn both (a double amount) of the barrel pieces at the same time. A quick call should clear that up.
You should also check on what exactly comes in the way of a deburring tool. The Essentials kit seems to come with other barrel trimmer guides, but the Basic only comes with one. You will appreciate NOT having to buy the other sizes of barrel trimmers when/if you decide to buy pens that have larger fit up pieces.
It is also important to note what they say about their mandrels, and you should take to heart with their bushings as well. CS madrels and bushings probably won't be compatible with other kits or pieces from other vendors. A loose bushing is worse than one that doesn't work at all as you will turn out a poorly fitting product with a poorly fitting bushing.
So if you like the CS pen lines, you are in luck. All those things together in their kits save you some money and give you a chance to get started.
As far as CS goes, I have been buying kits, fit ups and supplies of all types from them for years and never had a problem they didn't correct.
Robert