I suggest to go with ICS because JB has better features but it will spoil the life of battery and in six months you will require a new battery. Also JB has bug in compass, it will show wrong direction. Few more bugs are there.
Few other person have also downloaded ICS Firmware from my link and they have installed ICS successfully. I think either there was some problem during your download or you are using a wrong method to extract these files.
You don't need to extract these files individually. Please install Winrar in your PC and just put all three files in a folder. Double click on any one file out of three, Winrar will open, just press Extract. You will get a folder and all files will be extracted inside that folder.
After extraction, you will find that file size of fat_sparse.img is 801,368 KB. Total folder size will be 1.38 GB