First i would backup and delete any games on PS3 #1. This will make the backup process way faster. Then I would backup thru official means on a FAT32 formatted usb drive. It will likely take hours.
Then, since the process would erase the hard drive on the new PS3 I would keep it intact, remove it and I would just pop in a new 256 or 500 gb sata SSD keeping my PS3 nice and fast and cool and reinstall HFW when asked for it (not OFW unless I need complication).
Then I would restore my backup on new PS3, install my CFW thru XMB then copy my games back.