For mobile setup, I would suggest trying out a ThinkPad - carrying just 1 piece of equipment is always the best, and usually people would find the ThinkPad keyboard agreeable.
Otherwise, then it would be a Surface Pro 4 (or similar form factor computer) + keyboard setup. And I suggest HHKB for its light weight and size or something like Pok3r or GH60.
If you really want a 75% which is understandable if you need to work on codes, then in China, it's easy to get a PLUM 84. PLUM 84 is decently built and has relatively light weight capacitive key switches at the 35g, oh, and it's fully customizable and programmable. I've heard some of them can even support dual mode (USB + bluetooth). Other working-out-of-the-box choice would be Noppoo Choc mini, where you have many options for Cherry switches and Gateron switches. I believe they've fixed most of the firmware problems existed in their earlier versions. Both of these Chinese 75% keyboards mentioned have the 5.5x space bar which is a pain in the ass to find replacement keys if you love to play with caps; however, these space bar caps themselves on the two boards are of decent quality made of thick PBT and thick POM.
Other 75% options are much more expensive and for most of them you need to make customized orders from makers: I really like Red Scarf 84 and Duck Octagon but they're not as mobile with those feet.
I am a believer of the 75% form factor. I think it should be the modern standard event for desktop computers and the number pad should be located on the left hand side of the keyboard if one ever needs that.
Please show us what you end up, there are so many keyboard clubs and sellers and makers in China.
