If you are going to run batteries in parallel, they should be a matched set. Otherwise, the older/larger one will deplete the newer/smaller one and prevent full charging. If your batteries are not going to be well matched, you need to use one at a time, and not together.
Whether your larger solar panel is going to be enough depends on your usage, and what the real output is. Solar panel output falls off very quickly if shaded, and you will only get near full output if the panel directly faces the sun. The rule of thumb I know says you get about 1/4 the rated output averaged over an 8-10 hour day. This would be 8-10 amp hours per day.
The 45 watt panel will probably be enough if the only load is occasional use of the water pump, and LED lighting. Fans (including the heater fan) will likely suck the battery down faster than the panel can replenish charge. But only experimenting will know for sure.
just my experiences