Identifying manufacturer (brand) of toilet from a photograph
I understand the reasoning behind your question but you should never "browse" for parts without first laying eyes on the parts you need, unless you like bringing/sending them back. There are numerous manufacturers with models that look just like this. Even if your wild guess is correct, manufacturers use different internals for the same tank and bowl depending on model. They also change internals year to year but continue to use the same tanks and bowls. 

Wait until you return and you will find manufacturer and model information stamped into the back of the tank. More importantly you will be able to see the parts you need.