Plastic propane/battery compartment

2015 T@B 320. My T@B came with the plastic propane/battery compartment in front. A few years ago the weld on metal vertical support on one side broke. Trying to weld it back would probably melt the plastic so I tried JB Weld. JB Weld may be strong but its brittle so with "average" road vibration the patches broke again and this time the other vertical broke and the plastic cracked throughout. I need to replace the compartment. I plan to go with diamond plate compartment like on the Outback.

I checked with the RV place where I bought the T@B and the Outback one is about $650 plus installation. I want this one to have room for two batteries and the propane tank. Seems to me I read a thread that said there was room for this in the Outback compartment but it was a tight squeeze. I looked at a truck accessory store today and they have a diamond plate "tool box" 47"(L) x 19 1/4" (H) x 15" (W). This fits the batteries and propane tank with dry storage to spare. This is also about $650 plus installation. It would be bolted onto the trailer tongue with propane and battery holders bolted onto the box.

Has anyone done this? Are there any advantages to the factory compartment and disadvantages to what I'm thinking about?

Thanks