th350/400 to np205 adapters are pretty pricy... you'd be better off just using the factory toyota transfer case, you'd end up spending the same for the adapter, but nothing for transfer case(unless you rebuild it), and driveshafts may be cheaper??
it does depend on how much power you're putting out tho too. I'm not sure how much a factory yota transfer case will take, but i know a np205 will take a decent amount, and supposedly dana300's will as well.
i'll probably run either a TH400, or NV4500 into a Dana300. I plan on making about 450-500 torque though... and i beat on my truck like something i won't say. Not to mention, i'll be driving it daily to and from work.
things are pricy, things are cheap, it all depends on which route you take, me personally, i've spent over a grand now, and don't have much to show for it... i'm guessing my engine build will be about 3500 using cheaper parts(cast crank[hoping it'll hold up], fact rods, maybe forged, forged pistons, cheap ebay heads, or iron vortec heads, free intake manifold & water pump from my neighbor, and 100dollar 750cfm holly carb, cheap distributor) tranny will run me about 1600 for nv4500 after core costs, + s/h. then flywheel/clutch/pressure plate which is i duno how much. adapters to sbc, and adapters to dana300 from a jeep will run about 1200 total. then custom driveshafts(duno $$). body lift you can spend anywhere from 200-300+. I spend 331 on mine from 4crawler offroad. but i got the polyurathane body bushings. Radiator, you could probably make your own mounts for a radiator you get, fan you could do the same, i personally spent WAY too much money & got mine from AA... big mistake, but everytime i look at it i'm still happy, go figure?!?!
Best thing to do is to call up AA, i found they were a few bucks cheaper than northwest offroad.. i duno, maybe things have changed, AA does keep saying they've gone up in price. Personally i liked AA's customer service(over the phone) much more than i did NWOR. They were more open with information, and they were real friendly. I duno, maybe it was just me??
Honestly, i'd make my own radiator & fan setup from summit, engine mounts i'd make my own if i could weld better(but i'm just beginning). And to be honest, to do it cheaply, get a "not too powerful"(stock) 350, mount it to the th350, and run the factory transfer case. You'll still have double the amount of power a 3.0 or 22r will put out, crappy gas mileage, and a v8 yota.
As far as a "Kit" though, no, there are no "Complete Kit"s. It's all part by part.
PM me for any other info, i'm not the most knowledgeable, but i'm willing to help if i can.