Caltar lenses have already been mentioned. These are mostly rebranded Schneider and Rodenstock lenses, originally sold by Calumet and they sell s/h for less than the equivalent Schneider or Rodenstock lens. Here are some equivalents (I hope these are correct):
Caltar-S II: Schneider Symmar-S (good)
Caltar-W II: Schneider Super Angulon (wide lens)
Caltar II-N: Rodenstock Apo Sironar-N (an excellent lens, recommended) or Grandagon N (Grandagons are wide)
caltar II-S: Rodenstock Apo Sironar-S (better than the rest, more expensive, large image circle)
Caltar II-E: Rodenstock Geronar (a budget lens, but very good for the price, smaller image circle, slightly slower at f/6.3)
Caltar S: Ilex Paragon? (OK, but older than most Caltars)
Bear in mind that there is very little real difference in the performance of these lenses. For a 150 mm I would go for the II-N or the II-E depending on what is left in your budget.
There are many other good and cheap 150 mm lenses, of course.
I have a couple of field cameras, an Ebony and a Chamonix - from the first batch of 4x5 Chamonix cameras (designated N-1). The Chamonix has very good movements for a field camera. It's also very light. Maybe look for one of those used. There are, however, some lightweight monorail cameras that don't take up much space, as timor said. For example I carry my Arca Swiss Field Compact around more often than the actual field cameras I have.
Good luck,
Helen
Don't forget film holders (also called double darkslides) and a decent tripod