Of the options listed a brew fridge would be my choice. Itmakes it much easier to provide a temperature-controlled environment for fermentation and allows for cold crashing.
I have a floating dip tube to transfer from the fermenter to the keg, but I still get a tiny bit of sediment in the keg.* Sometimes enough to notice in the first pint, but usually not notice until the keg is finished and I see it on the bottom when cleaning.
If you are transporting a 5l keg you...