What I have found is that a) Toyota models tend to share some parts, so you might be lucky and the part that brakes will be the same as on LandCruiser, or b) Official Toyota dealerships should be able to order ANY part and have it shipped in roughly a week - although how that will work in South America I have no idea.
We've found this to be the case and sometimes you can even have luck using parts from other makes/models. In most of Latin America, you have to physically remove your part and bring it into the parts shop so they can compare it with the new parts in stock. In Bolivia I had to rebuild my brake calipers and replace the pads, if I remember correctly we found the pads from an 80 series were an exact match for our 4Runner, and the caliper seals were for a Nissan Pathfinder. Don't quote me on that, it's just an example.
We've found the Toyota dealerships to be typically useless, except for oil filters (since the box says which motors are compatible for the filter). Of course our Toyota is 27 years old and most of the world just uses cheap aftermarket parts. When going to the stealership, it helps if you look up the part number ahead of time. An incredibly useful website is
ToyoDIY.com where you can enter your VIN and find the part number for your specific vehicle, then you can enter that part number and cross-reference the same part with different Toyota models which may have the same part under a different number(including the different part numbers for markets outside of N. America). This way, you can go in armed with several different part numbers for the part you need, chances are much better they'll find it for you. Also note, if you need Toyota to ship a part it can take over a month...that was always the time frame that was told to me by the parts guy behind the counter.
As far as a sink goes: what Navman said makes sense when you're at an official campsite or in the bush, but we've really needed a sink when "stealth camping" on the street in a town. Once we get our 4Runner stateside, we will be trying to stealth camp a lot more to avoid expensive campgrounds in between the BLM & state forest camps. A sink with a removable drain jug will be necessary so we can easily drain it at a gas station or on the side of the road. Otherwise the dishes pile up and we get too tempted to go to a restaurant for our meal. In Latin America, most travelers would probably just wash their dishes right there on the street (since you don't really need stealth to camp on the street there) but I always feel uncomfortable doing that.
Bikes: I think only if you're driving a monstrous rig and can afford the space to have a locking/sealed box to store it in. Otherwise the bikes get damaged from the elements and it's one less thing to worry about getting stolen. I've only wished we had a bike a couple times in the past two years but then I think about the pains of traveling with them. If you're really itching to hit some trails on a bike, usually you can find rental places. Just my .02
