Yeah trichman, you got it. Get the cartos from David and the adapters at the other site. David's building up his hardware supply and I'm sure he'll have these adapters sometime in the future. Their a small, inexpensive item. And I don't think you'll regret getting David's cartos. They are excellent!
On the syringe, I use a 3ml syringe with a 18 gauage needle. No particular reason ... and when you buy them just ask for a larger needle if you wish. I think the smaller the needle number, the larger the needle. You might find it easier to get larger needles at a Feed Store than a pharmacy.
A couple tips. One, put some Scotch tape around the ml markings on the syringe you want to preserve. If you don't the markings will disappear quickly. I usually take the needle off and fill the syringe without it, then put the needle back on. Aspirating through the needle can be difficult.
Keep a small pair of needle nose pliers in your arsenal to just snug up the needle a little bit. After the first time it comes off the syringe and you blow juice all over your face and everything else nearby, you'll determine that its a good idea to do this.
Some people take the syringe plunger out and fill the syringe from the top. I've tried this, but find I lose juice when trying to get the plunger back in, I make a mess and end up with a lot of air in the syringe. Probably just me.
Another thing I do is use two glass condiment cups. They hold an ounce or two of liquid and are available on line and usually at candle shops. Or, a shot glass would work just as well.
If I'm filling several CE2's (for example), I pour the liquid into the condiment cup and draw it into the syringe from there. Its a lot easier. When I finish (and I try to keep only 30ml bottles or larger) I use a moistened Q-Tip to help drain liquid back into the juice bottle so that its not wasted.
You're smart for having juice aging while you have another supply for use. That's the way to do it. And Christmas is only about six weeks away, so you'll be having that fine, new eGo before you know it. Happy Vaping!