I've come to think a good TLR is the sweet spot for travelling light with MF---good focussing mechanism, good lenses, manageable weight and bulk---but you generally have to accept a fixed lens, and again it's hard to get built-in metering (and if you do it's usually selenium).
I love my Pentax 645N. Yes, the grip is towards the back, but it isn't that likely you'll be handholding it with a huge lens. It's not the heaviest camera out there, but it's not a featherweight either. I can handhold mine with the 75mm or the 45mm on it, but not the 120mm. It also has two tripod mounts - one for horizontal and one for vertical, which I have found very helpful.