
Its all good, I got you ... The Kraken, the difference between the two is a parts package, so I would go with the more expensive one. I have a SS Kraken made by this same manufacturer and one of the things that I liked was the generous supplies that came with it .. I still haven't used all the ss mesh, and I bought it 6 months ago.
You should choose your wire gauge based on the resistance result you want from your build. Higher gauge = higher resistance, lower gauge =lower resistance.
If you are a planning on running it in dual coil, I would use the 32 gauge because its thinner, and easier to capture both coil leads on the positive post. If I had one criticism for this particular Kraken it would be the washer on the positive post. I found it very difficult to get a good dual coil build with 30 gauge, had more success with 32.
But I also prefer the Kraken in single coil mode any ways ... the Kraken is a great RBA, flavor w/ss mesh is stellar, and vapor production is second to none. The air flow control is the best on the Kraken.
Battery: Sure a Sony is fine if you choose, but that is a lot of unnecessary power for a regulated device that will never use even half of the batteries current capacity. But again, there is nothing wrong with using a Sony VTc5. Any quality IMR 18650 will due, and Sony is not the only good 650 battery out there. There is AW, Samsung INR, Panasonic, some Sanyo's and LG's.
Being that you are buying for a regulated device with a limited output of 5A, any of those that I named above will suffice.

Hope this helps ya!
ETA: whoops .. I lied .. the difference between those two Krakens is the manufacturer .. the parts packages are similar, but I am more familiar with the manufacturer of the $18 Kraken .. I have no idea who makes the other, or how the quality would be