The 1500 looks like the most serene and "general purpose". But there are some exciting ones in there: 9528 looks intriguing. 2127 is another non-offensive one i would imagine for the type of shot you want. 

But that is just going by similarity towards the blue/white cloud render style i suggested earlier.  I am not a pro, nor have i ever shot with anything like this, nor do i own anything like this.  It is just an educated guess i suppose based on the fact that too much colour explosion in the background detracts from the subject and also that harsh lines attract the eye too (as per 945 - which would actually make a great photo study background i think).

Btw - hand painted? You dont cut corners here do you?

edit to add - 912 doesnt look bad either.

"In every colour, there's the light.
In every stone sleeps a crystal.
Remember the Shaman, when he used to say:
Man is the dream of the Dolphin"

Rich Meadows Photography