A single roms for differents counrty topic

Hello,

I work for a group wich sell smartphone and tablet.
Several manufacturers offer to build device.

And we want integrate many apps in ROM.
My problem is we want to sell in differents country and some apps should not installed.
And we want build a single ROM for all country.

There are differents solutions for solve this problems?

Thank you

PS: sroory for my bad english.