Hey Redlux,
How sure is your dealer with the upgrade features on the SR5 as you mention. Especially the one with steering wheel audio controls?
Because toyota's press kit website hasn't released any details yet on a upgrade. Maybe in the near future? I don't know.
Anyway if they do, do a upgrade as mention with wheels i'm guessing they'll be the one's from hilux invincible in Great Britain which are 15 inch. Grill will be most likely be a add on centre grill plate, which you can buy on ebay anyway.
This is my opinion on this anyway, but if any other members are curious just look at other toyota websites from Thailand, Malaysia, & Great Britain, to check out what comes standard & opitions on Hilux's released in other countries. Try the toyota world wide web site, www.toyota.co.jp/worldwide. Hope this helps.