I use a Danforth (well, copy of) on my BRe. I think it is 4.5KG and only has about 3-4m of 8mm chain. I have anchored on sand and mud and it hasn't come close to moving and I wouldn't anchor in the sort of conditions that would cause it to drag! I keep it in a bag next to the CB case but my anchor has the cross bar/arms and they only just fit between the CB case and the locker, such that I am paranoid they will damage the boat, so I'm either going to cut them down and/or may get a small anchor that my wife can more easily handle (given that even the 4.5KG is overkill for lunch stops).
The other consideration on the BRe is that you don't want to be going forward to use the anchor. I have a line attached to a forward cleat that come back to the cockpit. That has a snap shackle on the end and when we're not at anchor that is normally clipped to a rowlock, or similar. When anchoring, the anchor is deployed from the cockpit, let out to the right length and the snap shackle is clipped to a loop in the anchor line. I use a butterfly knot to make the loop. I leave the loops in the line so there is normally one to use, but if there isn't then this is a quick knot to tie. Obviously the anchor warp is kept in the cockpit so you can haul in again, but it is loose enough such that the tension is from the forward cleat and the boat sits at anchor properly.