Multi language SEO domain tips


I am building a multi language (German / English) cs-cart website and was wondering what the best way is concerning domains.

I have our domain in .de and .com

Normally I would prefer to just use the .com domain but it is a known fact that Germans prefer buying from a .de domain and Germany is our primary market.

In the rest of Europe I would like to advertise with the .com domain.

What do you guys advice? I would love some tips as I’m really new to all this.