I have these arms in my daily R33.
I had issues with bolts starting to come loose the resultant knocking noises etc, but nothing too major. I just modified the bolts (that bolt the arm to the chassis) so they had an extra lock nut where they stick through into the engine bay.
If you spend a little time fitting them, use locktite, extra lock nuts etc they work ok. Can be a bit of a pain to adjust though (my tyre guy hates me now )
Also, there aren't a lot of other options unless you can afford the expensive cusco or ikeya formula arms.
EDIT:
Check first to see whats bent, it might not be the upper arm thats damaged.