My Girlfriend and I ran this stretch last fall in our Duckies in only 3 days + 2 miles the first day (put on friday night, took off Monday afternoon)...When we put on the water was at 345 if I remember correctly...under 400. We worked really hard with some looooong 20-25 mile days but got er done. In the goosenecks the current is strong and fun and any level. When we got off and I looked, the water spiked to a little over 700 (I believe I estimated 650 at the time we ran Government.) Definately scout Government.
Our final day was a pain in the ass, it always is on this strech though. As has been posted on this forum before, the last 16 miles, basically from Slickhorn down is the lake with really no current at all. If you can, try and break this stretch up into two days. At lower water the channels can actually be easier to read because they are more obvious, but we still drug our boats numerous times...even in Duckies (overloaded duckies though!)
We were fully self-support and it worked out fine. I don't think I would take a raft down there under maybe 600 or 550, but in ducks you should be ok. If you have the time I would camp at Honniker (mile 45) and do the hike to the rim. We did the hike a week before we launched from the top down last spring and it took us about 4 hours. From the bottom up I bet it would be closer to a 3 hour job...it is 3,000 elevation change over 3 miles I believe.
Stop at John's Canyon camp if you can...it is awesome even if the water-fall isn't running. Stay at Slickhorn and hike into the canyon, swimming pools and such. Grand-Gulch camp offers hikes up into the Anasazi realm and whatever you do DON'T camp at Trimble camp...it doesn't exist any longer (at least from what I remember last spring). If you can get a Navajo permit, try and score Oljato camp for your last night and hike up into that canyon as well....awesome!
Go for the trip, hope it is a good time for you...pack light!