4/5 weeks in fiji tommorrow, comments & useful advice please

hello friends. i leave tommorrow for fiji for fivish weeks. at the moment im thinking of a week spent heading from nadi to suva, stopping in korotogo (& from there heading to korolevu & natadola). check this post in suva, then catching ferry to ovalau (via calaqui maybe) & spending under a week/week there. after that taveuni, for a week, probably basing myself in somosomo, or maybe matei, but going walking & exploring, and heading round to bouma & lavena, which ive heard big things about. then head back to vitilevu, & go back to nadi via rakiraki area & a few days in koroyanitu(?) nat. park. hopefully this should leave a bit of time for either namosi or nausori highlands at start/finish
basically i have veryvery little money, and my main reasons for coming are for full power nature and beutiful walking and cruising about, and some beaches would be nice (as brittish beaches arent too special), but i may have this covered with coral coast & calaqui??.
so...is levuka the best place to stay in ovalau (how about rukuruku?), also does this sound like to much in too little time? would it be worth cutting out ovalau or calaqui or somewhere on coral coast or vitilevu highlands out to create more time (bearing in mind i dont like to move around too much, & enjoy chatting to a few locals)? also ideas for cheap accommodation around taveuni, korotogo(or anywhere coral coast), & possibly a village in vitilevu highlands that doesnt mind europeans too much to stay for a night or two? also is it worth staying in savu savu for a while (bearing in mind its cheaper to go direct suva-taveuni, ive heard)?
pardon for the long post but ive a few questions.
cheers people, oh & general comments would be much appreciated too. thanks!

also, does anyone know anything about matangi is. resort (taveuni) or crows nest resort (korotogo), and what do people think of 'the beachhouse' (somewhere on coral coast), theres free sea kayak use which looks mint!

Some photos and write-ups of places you mention at my BLOG.

With some planning, and maybe a flight here and there, I suppose the itinerary is manageable.

Considering what you seem to want, I'd cut out the coral coast. Levuka on Ovalau is a unique place, and can be easily combined with a couple of days on Caqalai or Leleuvia for some beach time. Better there than the coral coast.

Naqara, a bit south of Somosomo on Taveuni, is more of a town commercial center, or what passes for one on Taveuni. Probably more budget accom there. I didn't much enjoy the atmosphere of Matei -- far too many mid- to upper end resorts with private property signs at the entrance. I stayed at Lisi's guesthouse (budget accom). Staying at Lavena for a couple of days will put you in the middle of the forest reserve area, with jungle walks, waterfalls, etc. South Taveuni is much nicer than the north (Matei) but I don't know what the current status of decent budget accom is, now that's Susie's Plantation has changed owners.

Savusavu on Vanua Levu is a yachtie's haven. Something of a curious atmosphere, with ex-pats having their club meetings in local restaurants, etc. I had the time to spend a few days there. If you have 5 weeks, consider giving it a miss, unless you're willing to try a fairly quick pass-through overland on the way back to Viti Levu. The local bus rides are long and tedious! I thought Labasa up north to be more interesting -- practically zero tourist presence at any rate. Big Indo-Fijian population.