The limit of tape is 1440 x 1080 i anamorphic, and it is best to go to blu -ray. But, HI-8 is S-VHS which is only digital 8 quality to DVD or back to tape. Adobe CS6 Premiere Pro is the way to go, you will have all the options, we use CS5.5.2 which is magic with a Mercalli V2 stablizer, and a DELL XEON Precision Quad Core with 15,000rpm "C" drive in Raid 0 with 12GB Ram, you will get a Warp Stablizer in CS6 included ,but, if not for a 64bit system Sony Vegas Movie Studio Platinum 12 is an amazing digital editor, at a tenth of the price..
DO NOT USE RCA cables you will get VHS quality only,.Firewire IEEE1394 will retain quality but, (not needed for 1920 x1080p from Canon 5D MarkII and III or Nikons). if you recorded in hi-8.
Good luck !!!!!!!!!!!!!!!