Salvatore, for New York style in a commercial setting, I'm not sure a WFO is viable. In order to accommodate 4 16 inch pies along with a fire, you'd be looking at upwards of a 50 inch oven, which will be a considerable undertaking. If you have access to very inexpensive hardwood, and craftsmen with considerable oven building experience, then perhaps this might be an option– perhaps, because of the size, a vaulted oven rather than a Pompeii, but if you're considering doing this yourself, I think an oven of this size is pretty ambitious.
The thread that I posted earlier involves a member in Burma. Burma is not the Philippines. You should have access to quality deck ovens. They won't be cheap, but, as I said before, an oven is not an area where you want to cut corners.
How about electric? Do you pay a lot for electricity? When you're dealing with obscure/unknown ovens, electric tends to be a bit safer than gas, and if selected carefully, can produce comparable results.