32 bit files for HDR question

It's been awhile since I have used HDR, but I do remember that Photomatix is a far superior program over any Adobe product. Here would be my work flow.

Take your Raw images and process them with NX2 to 16 bit Tiff's, go directly from there to Photomatix as a standalone, and finish with any remaining touches in CS5. You don't need LR4 at all. Also and this is fairly important, don't convert anything to DNG. It is an unnecessary format that ultimately harms images. Do make a copy of your raw files though, and work with the copy. Adobe's HDR Pro is just not that good.