location portrait advice. HDR and Flash?

[Peter Blake]

I have a nice waterfront location, where am planning to shoot in the golden hour. there's a bit of decent urban architecture in the background, which adds huge amounts to the shot. plus want a bit of sky. so was thinking about a subtle HDR (for the background). I am not yet at the stage of compositing studio portraits into landscapes plus, always think they look a bit fake, even when Joel Grimes does them.

Would be shooting the model with flash. has anyone combined HDR and flash in the same (in-camera) shot? any examples I can see online?