Yeah, I don't know that species specifically, but it sounds a lot like the growing conditions for Mangosteen in as much as "early shade," "long taproot," etc.
The mangosteen I bought has a pot that is a real pot but looks like the shape of Mark in Texas' picture of plastic ones, almost vial-shaped. It is at a point where it needs to come out and be planted, but was quite healthy in this thing. So I would say, just research how long/how much space the taproot will need at the 2 year mark, and make a container for it.
If you use the plastic water bottle, make extra sure to give it plenty of holes - firm plastic does not breathe well at all, so it will need a few more than some of the other materials that give more with the expanding and contracting of soil and the change in size of the plant. A few in the bottom for drainage, and maybe one every 2 square inches or something around for air circulation. There is no problem with putting too many, if it dries out to much you can just put a plastic bag loosely over it to help keep the soil moist.
You could also build a suitable pot out of scrap wood and drill holes, for something that will easily last the 2 years, especially if it will be outdoors some of that time.
Personally, I would just stick it in a bag that I stapled to the shape of what I want. It will take all of 2 minutes to make, and last 2 years. Punch a few holes, stick it in a vase or lean it against something heavy, and you're done. Only because I find hard plastic more difficult to worth with to make holes, and it holds moisture so well you have to be really vigilant about mold or root rot. Not impossible though, I just find it higher maintenance. The bag, if made a little loose, allows plenty of room for the soil to breathe and shift a little, which plants seem to like.
Maybe it doesn't matter for just one pot, but I do find that the obsession with gardening adds up quickly, because all it takes is successfully growing one plant before you find yourself starting to grow hundreds, and so nearly-free solutions become a must! I have hundreds of grown plants right now, and including the seedlings maybe a thousand, so if I didn't keep it simple I would be out on the street!