what gear ratio would i need to turn 33's on the highway with a samurai? and can i use the same gears with a 1.6 engine?

Either the 6.5 or the 8:1 transer case gears put you in the ballpark.  If you want to go with the diffs only, a 5:12 gear set would work.  But the highway might be a little bit of a push with the 1.3L. 

Do a search on 'samurai' and 'gearing' and you should find plenty of articles talking about what people like best.  You should also check out the reader rides to see what people are currently running in their rigs.

There should not be a problem running the same gears with a 1.6L installed.