Model sizes

[Pastscapian]

Hi all,

We are creating a model for a third party who will he using Vizard to create a virtual tour. We are modeling in Cinema4D and will be converting to .OBJ for import into Vizard. We have a few questions regarding this that we can't find answers to:

Is OBJ the best format?
Is there a rocommended polygon maximum size for the total model?
Is it best to keep texture all at the same size: 512 for example?

We won't be involved in the Vizard side of thing, directly, but want to make sure we supply a model that's going to import and work fine, without too many changes to be made. It is a detailed model, and this worries me a little.

Thanks for your help.

Pastscapian