Is that wireless adapter baked into the MoBo, or a modular item I could separately upgrade later to Wireless AC if/when desired?
I believe all of the time they're modular, and I'm pretty sure the antennas are standardized.
Recommended size for mSATA boot drive?
64GB is plenty for Windows and a lot of applications. But you should inventory how much space your applications take up. Windows normally takes up 25GB, give or take.
Other things of note:
- You can get a dedicated GPU as long as it has GPU switching technology (NVIDIA Optimus or AMD Hybrid Graphics/PowerExpress). I had a laptop that lasted 10 or so hours on battery even though it had a dedicated GPU because it had GPU switching. Otherwise, if it's 2D applications, anything will do really. You can get Intel's latest craphole of a GPU and it'll still do 1080p video without breaking a sweat.
- If you don't need the larger HDD or space right away, you can get a laptop with an HDD, replace it with an SSD, and put the HDD in a USB3.0 2.5" enclosure (you can get these for $20-$30). I did this with a few laptops and it's worked well for me. In fact, I ran a Minecraft server in this setup just fine.