Just get the floorpan specific for your year, or some people just buy sheetmetal, and fab a pan. check out this thread, http://forums.hybridz.org/showthread.php?t=106731 i believe he had rust in this area, watch the videos. you might be able to cut that piece off a junkyard z, or get it from someone who's parting theirs out.
You should be able to re-use most of the parts, providing they didn't need to be replaced anyways, and you didn't break them in the process of taking them out.
good luck