Well the Renogy stuff is all over Amazon, Renogy Rover MPPT controller. Here is the battery. and the price just fell a little more. $930 last night when I checked

https://www.amazon.com/LiFePO4-Temperature-Charging-Parallel-Road-Trip/dp/B0B5V6GVSW/ref=sr_1_4?crid=2I1OOLMZZDP4Q&keywords=300ah+lifepo4+battery&qid=1678390590&sprefix=300ah+%2Caps%2C109&sr=8-4

Don't get the Edecoa inverter and I do NOT recommend it. The power is not clean and will cause issues in the trailer.