with barbabatch you can use dither or not,
about dithering,
you should check www.gearslutz.com too
which is for me the best technical forum about mastering / mixing tech and gears..
I have been using Sample Manager v3.0.8 for the last few months and its perfect for batch processing. it cost $90 which is monkeys and worth it when you realise how much hastle it is co convert samples.