Two things that might help....
First, I can tell you that I have had several horrible experiences with loading W7Ultimate64 versus loading W7Pro64. I built up a xw8400 for a friend of my son, and had an extra unused Ultimate COA license. Loading that and then updating it was a great waste of time. It never settled into being a normal build, and this was from an official Microsoft installer optical disk. I then took one of my spare W7Pro64 licenses and loaded it up from an official MS installer disk and all went normally and with the usual updates I finally had a normal build. There was a huge difference, and I will never load Ultimate again. Ever.
The second thing.... it is odd that your installer cannot see your target drive. I personally would, at this point, download the free iso of DBAN, burn that CD, boot from it, and do a low level format of the target drive. Then, I'd go into Computer Management, partition it, and then do a long version of the NTFS formatting. Then, I'd target that with my W7Pro64 system builder MS optical disk for the build. Make sure to have BIOS set to SATA emulation of RAID + AHCI, or you won't get the correct drivers for that installed. Your Disk Management part of Computer Managment should be able to easily see the "raw" drive that DBAN results in, and then it can partition it correctly, and then you can format and load it correctly. Read up on how to make sure the special "system reserved" small partition is created in addition to the large OS/programs partiton.
