As far as the mini usb, don't worry; it's just the connection to the keyboard that is mini USB, which is probably the most common connection. The other end is still USB-C to plug into the computer. KBDfans may lube their stabilizers by default if you buy a built kit from them - that's what I did, but I'm not entirely sure if it's lubed or not as it has box switches. However, you could just shoot them an email. You can get their boards customized with nearly every MX-based switch (you can check their website for the huge list they have, I got Hako Trues) which makes it nice if you want to experiment a bit.
I can't say too much about the Anne Pro boards, as I haven't tried one myself, but have heard good things about them. Build quality really doesn't matter a ton imo, as even most consumer boards (Corsair/CM/etc.) will last for years if you don't abuse them; they're all plastic case boards anyways. For an increase in quality, you could get an aluminum case keyboard; then again, you're looking for budget options and dropping an extra $100 for a metal case really won't be worth it, and it makes the keyboard much heavier (my 60% Tina is around 5 lbs, which is significantly heavier than my TKL Realforce at maybe 1.5 lbs).
All in all, I'd say if you want to get a premade, get a 60% plastic-case board from KBDfans; with silenced Gateron browns, it comes out to $95 with Cherry stabilizers and an aluminum weight/choice of layout. AFAIK there aren't any consumer boards with them. If you're fine with learning to build your own, find your choice of kit and buy the switches separately. I do recommend a DZ60-based kit though, as it's commonly used, well made, and cheap.