RVers, I took some time and put several different 45 Amp power converters side-by-side to see if I could help you decide what you might want to buy.
I honestly thought I might be able to find a “smoking gun” – you know where I could say definitely “this is the best” or “this one is good to avoid”, but I didn’t.
Question: How do you know how many Amps you need? You first count all of your 921 lights and just use 1 Amp for each bulb. That can add up really fast. I would allow a few Amps to charge the battery. I think you can ignore the igniters for LP gas stuff, but for the water pump that would take several Amps (read the literature) for somewhat extended periods of time. If you can afford to buy a bigger (more Amps) converter and you have the space for it, this seems like a no-brainer to me. You can try the RV Power Converter Size Calculator.