1. Not a clue. But I ordered mine from Health Cabin, shipped DHL and arrived in Oregon at my house in 3 days.
2. Not a clue. Ditto to the above. Ohms don't matter so much with a Variable Voltage mod like the Vamo. I think the standard replacement ohm atomizer heads come in 1.8, 2.0 and 2.4 ohms. Just get a variety of them, as I said, they will all work, and will give you an idea of what ohms you prefer. (pretty much the same can be said for the cartos for the cartotank setup that baditude recommended).
3. Yes. Edit: if you want to run the Vamo in "shorty/stealth mode" you will also need to get AW IMR 18350 batteries. RTD Vapor is the vendor for batteries. Best prices, best quality, best shipping. Won an award for it (in the "best battery vendor category") last year and maybe the year before that, too.
4. I can recommend them, but it doesn't mean that you will like them.
I vape Mad Murdock's Radiator Pluid and Mad Murdock's 710. I also vape Boba's Bounty and Gorilla Juice from Alien Visions, and I vape WTA e-liquids from Aroma EJuice. I also like North West Vapor's Blueberry Cheesecake, (but no one else's). I vaped about 50-75 juices to narrow it down to those. I consider myself a picky vaper. Everyone's tastes are different. You might end up not liking any of those. Just because one vendor sells a "chocolate" juice and you like it, does not mean that you will like all chocolate juices from all vendors. Do a search for the "big RY4 roundup" thread, and you will see what I mean.
The following vendors have outspoken fans, I have not tried their juices, but there are lots of reviews out there.
Heather's Heavenly Vapes
Alice in Vapeland
and Mt. Baker Vapor.