Lithium battery protect system

I am working on a project to protect my lithium house batteries in a motorhome. It basically does three things when certain conditions are met. 

• Completely unhook bank from everything if over/under volt or over/under temp
• Turn on a heating pad if temp falls below 32°F
• Turn on a ventilation fan if a certain temp is reached.

I have this built and it works.

I would like to replace the relays on the right with mosfets but, I don't think I can do it all with just one on each circuit. I don't think the 5V from the Arduino can turn one on all the way. Would this circuit work with something like an IRF1407 for #2? Twelve volts should be enough to turn it  on sufficiently to handle those amps with a heat sink. Can I also use it for #1 since #2 wouldn't really draw much current? If this would work do I also need a resistor for #2?