I used the Feejee Experience to do mine as my time was limited.
They forgot to pick me up from the Airport (i did book the day before I arrived) but after phoning them they sent someone out right away at about 3am and dropped me off at the Sky Lodge hostel before starting my 5 day trip 2 days later.
The Sky Lodge was a funny old place, I think it used to be a 4* hotel that they gutted and stuck loads old bunk beds in to, but the setting is lovely and they still have the pool and the basketball courts etc. really good value for money and great staff.
I cant remember the name of the tour i chose but it took us all round the island and we did sand boarding, and saw the thermal mud pools where the rival tribes used to boil eachothers heads as punishment. and we spent a night on the beachcomber island and saw wild horses and kayaked over coral reefs. oh and juming off waterfalls into deep pools that was awsome!
If you want to do a tour I would recomend this one, wasnt to keen on Suva though and its horrid bony goat curry restaurant