It's a little bit different in arabic :) It goes this way:
the person who sneezes starts saying "الحمد لله", means "Thanks God", pronounced "alhamdo lilah"
then the other person says "يرحمك الله", means "God bless you", pronounced "yarhamoka allah"
then the person who sneezes replies "يهدينا ويهديكم الله", means "May God guides us", pronounced "yahdina wa'yahdiakom allah"
It's Muslims way and it's arabs culture too.
The other two sentences:
"I hope you are doing well" = "أتمنى أن تكون/تكوني بخير", pronounced "atmanna an takona/takoni bikhair" *
"I wish you the best" = "أتمنى لك الأفضل", pronounced "atmanna laka/laki al'afdal" **
* takona = male... takoni = female
** laka = male... laki = female
Cheers :)