I have narrowed down my selection for my G35 sedan wheels to these 2 choices.
I am leaning towards the Kumho but I have had good experiences with Sumitomo.
which would you guys recommend.

The tire size is 225/45/17 for a 17x7 rim.
According to my research this will result in a 45lbs wheel/tire combo.

 

I have had the HTR+ and now have the ASX... The Sumitomos were a decent tire. Cheap and grippy. The center tread wore out fast on them however and they became noisy towards the end. Also, the Sumitomos had a soft sidewall... I just got the ASX, so can't really say anything bad about them right now...

 

I had the HTR+ and loved them. I had the same problem w/ center wear, but they gripped like champs until I replaced them..I think I ended up w/ a little over 30k on them. Can't speak for the sidewall, as I don't much remember.