Milky transmission oil, need air filters

Orderd FRAM air filters but found out FRAM does not make them any longer. Napa has them for about $44.00 anyone know where they may be cheaper? Noticed some oil slick around the boat last time fishing. I ck trans fluid sometimes. Getting lazy causes spending $$$$. I had my engine overheat due to impeller raw water pump went out. Should have went through everything with a fine tooth colmbe. Trans cooler went south, I guess. Been having trouble getting a prime on my sbd engine since it the raw water pump was replaced. Need to find out why. I smelt a little battery acid smell a few times but did not find out why. Words for the wise. If you have a feeling something is wrong, it is. I need to ck out batteries entirely.