Adding a joist

[jupiter_19630]

Hi,
I need to hang a chandelier weighing approximately 45kg.
The current light fitting is in between joist's so I will have to install a nogging between to joist's.
I have been given some 4inch wide joist hangers and some 4 x 2 tanilised timber.
My question is, which is the best way to do it? Should I lay one 4 x 2 flat in the hangers or would it be better to lay 2 flat one on top off the other, or 1 on edge and fill the space in the hanger with an off cut or 2 side by side and fix the hook bolt to just 1?
Any help would be greatly apprecciated.

 

[^woody^]

Two, on edge screwed togther

 

[jupiter_19630]

So I'll effectively have a 4 x 4 joist and fix the hook bolt up through the centre of one?