Signature Plastics' list of which SA key sizes are available on each row can be downloaded from
here.
The only somewhat unusual keycaps would be the 1.75 Backspace (Row 1) and 1.25 Back-Tab (Row 2), and I can see those as being available.
Row 1 1.25u is not available though.
I don't think SA has sculpted numpad-Enter and numpad-+ but are actually using 2×1 keys. (If I'm wrong, please correct me)