The Alpha is a really great choice - I would take a look at the Fuji Pro 2 as well if you'd like a smaller body with better battery life and a master-of-all kit lens.
For the Sony, my first picks would be a Venus Optics LAOWA 15mm f/2 FE Lens. It's an ultra wide angle now aperture lens, so you can get tiny interiors and milky way shots. This is helpful in europe if you'd like to photograph the inside of an old train, or in iceland when you'd like to capture the majesty of the northern lights.
For a walk around, I'd suggest the Sony FE 24-70mm. It'll capture just about anything you can throw at it, and with f4, you can get as much in focus as you'd like. Great for churches, markets, graveyards, and you can even use the 50-70mm section for portraits! :-)
Hope this helps! In my posts, I'll try to include the lens details too.