I think the setup on the link you put above will be fine for now. Then like ccCapt said, look into the reflectors because they help a bunch. But you can make due for awhile until you are ready to spend more money on reflectors. I have the reflectors which ccCapt mentioned above, Lumenarc mini, and I think I paid aroud $115 each. So they are pretty expensive.
What made you decide on DE? I went with SE because the bulbs are much easier to change out and they have their own UV
protection. But you can't go wrong either way SE or DE are both good. Did you decide which bulb you are going with?