The Toyo is a great camera, but I do not see too many used ones come up for sale. The Chinese made 4x5s are actually quite good, at least the ones I have seen, so don't be too fast to discount either a Shen-Hao or a Chamonix. I have used wood field cameras for years (Tachihara, Zone VI) in all sorts of weather and climate conditions, and they are more robust than you might think.
A few other things, off the top of my head:
- don't buy a monorail. They work great, but a total pain to transport. I almost never use mine;
- 210mm lenses seem to be the easiest ones to find used for sale, but I think a decent 135mm is the best lens to start with;
- for hiking, F9 lenses are great, but they are much harder to focus on the ground glass than brighter F4.5 lenses. To that point, point, a F4.5 - 135mm lens is nice and small, but there is a BIG difference in size between a F9 and a F4.5 lenses in the 210mm and larger range;
- the older you get and the worse your back gets, carbon fibre tripods start looking better and better;
- if you do any black and white shooting, get a spot meter;
- get some kind of loupe for focusing on the ground glass. Cheap loupes are not all that bad, and while more expensive loupes are yes better, any loupe, IMO, is better than no loupe;
- depends on your style, but I only shoot B&W on my 4x5 myself. To that end, all my lenses have standard yellow filter filters on the front of them. I almost never use orange or red filters for my B&W shooting;
- Kodak Tri-X is my all time favourite B&W film in 4x5, but if you are new, I find Ilford HP5+ is one of the most "forgiving" films out there in any format for somebody just starting;
- any brand of black and white film, always, always, always meter and shoot at half the rated ISO, or close to that. I always treat Tri-X and HP5+ as ASA/ISO 200 films.