Once you get your guiderings (I have the Losmandy setup and damn glad I do) you can still use a webcamera to guide with even though it isn't auto guiding. You can use the Drift Explorer in K3CCDTools to guide off rather than looking down through an illuminated reticle. You still have to make the corrections manually, but it is far more accurate doing it this way, not to mention a hell of a lot easier on the neck. I think the LPI will work but don't quote me on that. The DSI will work with the latest version of K3, but you might be better off with a ToUcam, that's what I normally use. It's rare not to be able to find a star to guide on. I've only had to use the DSI once, and that was more for the trial of it than anything else.
Using film your guiding accuracy doesn't have to be a exacting as with a ccd either so you have a bit of leeway there as well. Check out these two sites for film.
I know it means extra cost for a scanner, but if I do film photography (and I still do. Ran off a couple of rolls during the Easter break. 1 of negative to get the settings right (cheaper to processes) and then a dozen and a half shots of slide for the final images to produce the attached composite image for a uni project) then I prefer to use colour positive slide film rather than colour negative print film.
Fujicolour Provia 100 (what I used on the project)
Kodak Elite Chrome 100 or 200 (if you can get it)
or if you can get it (very hard to get if it is still available. I haven't been able to for quite a while now
Kodal Ektachrome E 200 (professional)