Fins for Kombat 122 Tufskin Size/Type

Hi,
im looking for some regards about fins for the Kombat 122.
The serial 36cm Freeride flow seems a bit small to me (since im abt. 110kg) wit a powered-up 7.5m sail. is it possible to use more slalom oriented fins, because i like to ride with more pressure on the back foot. to me it seems the board with the original fin dislikes to be driven over the back foot...

best regards, thorsten