What he said about film holders - you can still buy them new but can get good ones used much, much cheaper.
You can also get Grafmatic holders with a bit of watching and waiting, that let you carry and rapidly (well, fairly rapidly, for 4x5) six sheets in barely more space than a standard double holder. I just picked one up to augment the 11 holders I have. That's almost an embarrassment of holders - 22 sheets in holders and six in the Grafmatic. You will probably shoot FAR fewer shots in LF. I sometimes go out and don't expose a film at all. On a busy day I might shoot 5 or 6 shots, though some people do shoot quite a bit more. It's still nothing like banging away with 35mm or MF though.
I generally carry six holders with 12 sheets of film, but I haven't used the Grafmatic yet. I'll usually load those with 8 black and white and 4 sheets of color, or sometimes two different kinds of black and white to suit mood and subject. I have never, ever, run out of film while out shooting, though I have left holders back at the hotel and headed back to swap out mostly exposed one for those loaded with unexposed film.
I'd have to see the bellows in person to have an opinion on it. What I do and is usually recommended is put the camera in a dark room, extend the standards all the way out for maximum bellows extension and remove the lensboard. Then I put a little maglight flashlight with the lens removed, so it's just a bare bulb, down inside the camera/bellows and look all around for leaks. You'll often find them in the corners. These can be patched several ways - gaffer's tape or that goopy plastic rubber repair stuff being the most common. If it's just some in the corners, that's fine, just patch them. Serious tears or a large number of pinholes usually warrant replacement. Mine is old and has probably more than a half dozen bits of gaffer's tape on it - works fine. It's not rocket science, just has to be light tight.
There are people who make replacement bellows, even custom ones, but I don't know much about that.
I asked about the boards because I'd like to replace my Tech III soon-ish but with my wedding coming up end of this month I don't want to spend for a camera now, as I'll spend over $1000 when I do, all in. But for $200 I'd be tempted, if I could use my current boards, or easily get boards and get my lenses mounted. One of the few drawbacks to a Tech III as a cheap intro camera is that the boards are not the same as later Techs and are hard to find (though they can be made easily enough if you're handy with tools - I'm not.)
If you're serious about getting into LF check out the LF home page with lots of info:
http://www.largeformatphotography.info/