Dunno if it actually works, but A20/A10 with an external antenna: https://www.miniand.com/products/Mini%C2%A0Xplus%20TV%20Box%20H34 https://www.miniand.com/products/Mini%C2%A0Xplus%20TV%20Box%20H24
Thanks. I indeed ended up ordering one of those. They probably still use the standard rtl8188cus whose driver sucks, but at least the antenna can be changed if needed.
Stefan