I second David's recommendation. for real 800 speed, with adequate shadow detail, Delta 3200 is perfect.
Fuji 1600 has a true ei of 500-650, but I never liked it, much finer grained than the delta, but the negs were too black and white with little in the way of intermediate gray tones.
the delta films are a nice family with 100, 400 and 3200 producing a similar gray scale. this lets you mix and match with a similar looking print.