What rope for long drop?

[heartless-iguana]

2mm? I think it should be thicker than for full or partial hang.
Also how to secure the other end of rope correctly, so it won't get lose or something?

 

[TheGoodGuy]

Just go with a thick rope since you are going to use a hangmans noose anyways and you can secure it either with a noose or a snuggle hitch knot