AMADEUS, Welcome.
To achieve the original look of an Okrasa engine, your best deal is a Wolfsburg West replica okrasa kit. It is probably the cheapest also as you buy new cilinderheads, inlet , carbs and linkage. A second hand Okrasa is expensive and need probably a rebuild.
Or you can find someone that can make you 2 equal inlet manifolds that fits the split standard heads with 2 regular carbs from a split with smaller jets...Home made kit like ET
It also work if it is done correct.
@Et: how is the drive ?
ZELENSIS, coachbuilt body from the 50's on a vw platform made in Belgium. Peter the heb detective