In some ways, you are in a good position: you have to keep your fabric purchases limited to what you can fit in that tub under the bed. You have a window--I wouldn't cover it. Not only do you need light for working, but it's good for the mood and warmth (unless it's drafty, of course).
I would "shop your house" first before bringing in anything new to set up your station.
a. Do you have a big table you could use for your sewing table, that has legroom and is the right height for your machine? Try to use the smallest iron you can. You can use a handheld steamer (portable, small, cheap) for steaming wrinkles out of the yardage, and use a small iron for your blocks.
b. Comfort is more important than space. You have to have your cutting height and sewing height correct so you don't get a backache/shoulder pain/neck strain after just a few minutes.
c. Since you'll be opening and closing what you store under your table all the time, make sure you get sturdy units. Drawers should be easy to open, not frustrating, solid enough to open with one hand smoothly. Some of those cheap plastic storage things on wheels are too lightweight and cheaply made--the drawers get stuck or if you yank, the whole unit moves. Ugh. THey're fine for things you don't need easy or frequent access to.
d. How close will outlets be ? You don't want to trip over a cord, especially if it's attached to a hot iron!