It sounds like you are nervous really just about going international. When you have crossed as many borders and gone through as many customs stations as I have, you will regard the whole thing as just a formality before the fun begins.
Don't think about getting an apartment until you get on the ground in HK. You will just find out that you have wasted money on something that did not make you happy. You must check out the districts and the transportation from any particular district to and from work, and to and from shopping for what you need. There are temporary rental or apartment shares being offered in this forum that you might avail yourself of. Personally, when I first hit HK, I would stay in a super cheap hotel like Chungking Mansions. Some of the places are flea bag, but some are well kept up. This will offer you a low-cost way to get a feel for HK. You can then adjust your plans according to your budget. You can pm me for a reference if you wish.
Before you get an apartment, go through this forum thoroughly researching different districts and especially the names of different apartment complexes and rental agents to find the good ones.
Come as soon as possible to get set up in HK before your assignment starts, because you don't want to be suffering the stress of the former, while you are trying to impress the people at the latter with your implacable calm.
If you are a typical American, you are addicted to media, like TV. This is not a figure of speech. It is a real addiction and 99% of what you watch on TV worldwide is junk, that merely propaganizes you into a false worldview. You can use this experience to wean yourself from TV. Don't waste your money either shipping or buying; and the cable and phone companies in HK are notorious ripoffs. Browse through the posts here on that.
You will get a taste on this forum that not all expats in HK are nice guys, and since most of them work in fields similar to yours, this will tell you what this lifestyle is really worth. You will find out that most of the expats are non-American, so when you are over here, you will find out what they really think of Americans (not what American media hides from you). They are not eager for competition from a yank to see who's king of the dung heap. So don't wear your heart on your sleeve, just so they can knife it.
The reason you come to HK or anywhere is for the native culture.