The main difference is that the Lunch Bus's power converter (the little MeanWell block) is half the power of the one on the Excalibus - if that still covers your needs, go for it! (In theory, the footprints are the same, so could put the 30W MeanWell on a LunchBus but as Jim says i've never seen one DIY...)
I also have several Excalibus, and apart from getting a little warm because I really need one more of them, they're great! I opted to add some cheap little heatsinks on the converters to help them out a little bit, but the datasheet also says that they're supposed to run a little toasty, so it's probably not really necessary.