I would recommend the Mamiya 7 for portability and excellent optics.
However, if you want a system camera then I would recommend the Rollei SL66. This camera has the lot - with bells on for landscape work – and is the nearest thing to a large format camera as it gets: in built bellows, 8˚ tilt to use the Scheimpflug principle for greater depth of field, etc.
Heck, if it was good enough for Brett Weston . . .
Bests,
David.
www.dsallen.de