Minoura Gamoh Porteur is in the same league as the Soma so it might be overkill. I owned two of them and they worked well. Wald makes a pizza rack but it won't handle 10 kg.

I replaced my porteur rack with a Nitto front rack with a Wald basket zip tied to it. I was never carrying much weight so this was an easy compromise. You could get an inexpensive front rack that attaches to the canti posts and fork crown and put a basket on top of it. You could do that for less than 35 dollars.