You might be best asking on a photograhy forum.
A lot of it depends on what quality you want.
I've got a Nikon LS40 which I bought in 2003. I originally bought a Minolta Dual Scan, that lasted a month and went pop. Got replaced with the Nikon that has now been repaired once.
It's a 135 format scanner and the results are top notch. It takes about 5 minutes to do a scan, then I'll spend more time working on the scan in photoshop. I've had nice prints from it including ones up to 30 inches.
Sadly Nikon no longer make scanners. The Minolta and Nikon scanners were way ahead of the other offerings.
Another option is to buy a flatbed scanner with a film hood. It'll scan all formats up to 10x8 inch. The problem with flatbeds is they were generally considered too soft for 135 scans (though again what quality do you want). One advantage of the flatbed option is you can easily batch scan with 135.
Technology has moved on, as have some of the scanner manufacturers sadly, I don't know anything about the quality of the current crop of film and flatbeds.
Another possibility is using a slide duplicator (fits on the end of your lens) and a lightbox. Quick and easy, but again it all depends on what quality you are after.
As for scanning 100's of negs. That's a nightmare, or a very long term project, unless you invest 20 grand in a proper lab scanner which will give ultimate speed and quality.
