If your taking a landy them you will need a lot of spares! Agree wilth Alford in that a spare alt should be taken along with some other bits. no need for a land anchor and a winch is personal choice.
as for boxes, Zarges come highly recommended. ive got 2 of these and they are great for sitting on, standing on, air tight, dust proof etc. sturdy, lightweight alu.
also very good at a fraction of the price. you can build them up as you like too, loads of sizes, combinations and options. very sturdy plastic. not tried to sit on one yet though. steer clear of most household boxes because they are made from brittle plastic and will crack/shatter. eventually they will be good for nothing and you may aswell take everything in bin liners! one other point is that both the zarges and plastor boxes have raised ridges on the lids so can be stacked neatly and securely.
you should have made a list of everything you want to take by now. split this into sections then work out what size boxes you will need, how many you will need. are the items heavy? would it be easier to split things into 2 boxes? etc etc.
If you want somthing that is a bit stonger you should have a look at Space Cases, they are sold over here by ARB, but you should be able to find them somewhere.
They are a bit pricey but they are almost impossible to kill and they do a good job of keeping the dust out.