Quote - " LIGHT MODEL: global ambience"

I would not use global ambience. Like I said, I would use GI (global illumination), specially if this image is intended at a professional audience.

Quote - " ANTI ALIASING: 77%  SET ON AuTOMATIC (Ultra)"
Ultra has AA on 80%, not 77%. So, you probably mean "Advanced effects quality" is 77%. That's ok but that's more than what you need for this image (there's no advanced effects here). So, that's using up render time without much benefit. I would use "user settings" and place this at 46%, that should be enough for you and will decrease your render time considerably.

Like I said, Ultra has AA at 80%. For this image that's probably not enough (vegetation tends to need higher than that). Like I wrote before, I would go for 95% but you can change that only in "user settings".

Quote - " Also alot of settings in the Anti Aliasing box....

1. do you use automatic?
2. whats with subrays per pixel?
3. do I mess with texels per ray?"

No, I dont use automatic, I use "sharp". But you should try several to see which one you like the best.
Ultra has 4 and 28 as min and max of subrays per pixel. I would say 4 is too low, I would go for 10. I would say 28 is a bit too much but that's ok, just a bit more rendering time.
Texels per ray is for texture antialiasing. That's normally useful only in very special situations, like moire patterns in the horizon or similar. Your image doesnt need that, I would say.

Quote - " Could be AA or spectral sunset? (Im used to 2:3 settings in Maya mental ray LOL) would your recommend AA setting be similar to 2:3 ?"

Sorry, I dont understand what you mean.