Mark is a great guide and based in Belize City so if you arranged a tour directly with him, you could fly into Belize Municipal and he would meet you at the airtstrip and return you back to catch your flight once the tour is done. This would be my choice as it would allow more time with the guide/driver to experience Belize.
However, you could also fly to BC and then on to the Cayo district and meet a guide there. Ruins in that area are Caracol, Xunantunich, El Pilar & Cahal Pech.
CND, Clarissa does make a great relleno and chimole (the black soups!).