Well, not being an analog sort of guy, I probably would have taken an
"analog computer" approach - negate U1-R1*I1, add to U1 (gives R1*I1),
multiply by appropriate scale factor.  Three opamps (still one
package!), if you're dumb.  I'm pretty sure it'd condense down to one
if you're clever; probably look a lot like the circuit you posted, too...

BillW