New to oval

[tazzy]

Ok i am new to the oval dish issue.Presently i have a duel lnb with the basic 18 " dish. Orignaly form North Carolina would love to get the other channels.I am using two hu cards in my ird. The recievers are.(sony A-50)(Drd420re)(drd222).Will these ird pick up the extra channels or do i need a bs ird that wont allow the h card to work.Can i just replace the dish and put the oval on.Or is there more to this.
Thanks
tazzzzy