Sound advice from Obelics but I think the main appeal of a Kart campaign is the options you get. You can make a solid army from basically all their major areas (Africa, Sicily, Iberia, Gaul) and have the economy to do so. I'm running a Kart campaign atm and I did the opposite, concentrating on Africa and Sicily first.
Mate if you wan't to go to Iberia, why not, you'll still have a lot of fun kicking the Romani about with your Scutarii
Cheers