With the 12-inch MacBook, I'd get the latest you can. The processor is a little underpowered compared to the rest of the lineup, so a more recent model might mean the machine is usable for longer.
That being said, if you're already looking at the MacBook, then it's probably a good machine for you. You're going to be familiar with the tradeoffs (nothing a good docking station or set of adapters can't mitigate). I'm not going to defend the 11-inch Air; mine is a 13-inch and I love it, but if portability is your primary concern, then you can't get much more portable than the MacBook.
I just got a few of these and stick them on the ends of my usb cables:
AUKEY USB C Adapter, [3 Pack] USB C to USB 3.0 Adapter Compatible with MacBook Pro 2017/2016 , Google Chromebook Pixelbook , Samsung Galaxy S9 S8 S8+ Note8, Google Pixel 2/2XL - Black https://smile.amazon.com/dp/B01AUKU1OO/ref=cm_sw_r_cp_api_glt_fabc_J99KB18VK187W39BYYPH?_encoding=UTF8&psc=1