Any of those choices would be good for you.

It is important to learn to do your own maintenance so you can save money and have the satisfaction of doing it yourself. Ordering a bike off the internet makes this even more important because before you ride that bike, you'll need to go over it to make sure it is put together correctly. Cheap wheels can work fine but you need to make sure they are tensioned evenly. I highly recommend reading Sheldon Brown's articles: Articles about Fixed Gear Cycling and Equipment and Singlespeed Bicycle Conversions

I would not overthink your first bike too much. You'll learn a lot from it and by the time you are ready for another one, you'll know what you want; what works and what doesn't.

I'm 5'8" and ride 52-54cm bikes (measuring the effective top tube length). If you get a 54cm, it'll still be fine even if you put on another 3" or so.