Depending if your alternator is able to deliver it, you might go for the DCC1212-40 (40A version)
It's currently on sale at the German Renogy store for 130 eur
I think the 40A is more suitable for a 280Ah bank. If you ignore any available solar and plan to be able to use it in the wintertime as well, the 20A might be too slow. If you use 60Ah / day it requires 3 hours of driving to charge with a 20A.
I have gone for the 40A version, and installed a switch on my dash, so I can manually disable it if I want to (for example on a full sunny summer day, the solar will work, so no need to charge it by the alternator in a 2-3 hour drive). The sun is free, so if it takes a whole day to top-up the cells, who cares.