I am not convinced that a flapped glider will land in a much smaller
field than non flapped glider. I owned a Discus2, and I landed it
out...more times than I would like to discuss in this forum. I am not
going to go into field landing techniques, but I could land very low
energy, nose high, and stop in amazingly short fields, without hitting
the nose on the ground. When taking the glider to the hanger I would
touchdown before the beginning of the hanger and pull around the
corner. total rolling distance is under 130ft in light wind
conditions. How many times do you pick a field with that little
distance? I cleaned my brake regularly to keep it in good working
order.

I know own a flapped glider. Would I go back sure. However I like
25.5meters and anything under is just no fun.

So looking at the gliders that you listed. What fits your wallet? What
fits your body? What looks sexy (to you)? What finish is in good
condition (unless you like sanding and painting)? They are all good
gliders, if not they would be sitting on the market cheap...but there
is not much sitting on the market, and it is not cheap.

On the trailer topic. Nimbus 3 in Pfieffer trailer vs last generation
Cobra trailer....time difference to rig is about 3min. You could get
rid of that with a trailer ramp jack.