First choice ATI in a 4x24w setup.
Second choice would be a Tek fixture in the 4x24w setup.
The Coralife you mentioned will not house SPS. You will be lucky to keep softies with only 2 bulbs. If you are serious about coral you are going to need a 4 bulb setup.
If you want to keep it super cheap and are willing to sacrifice some quality and performance, you could look into the Fish Need It stuff. I would change all the bulbs though and that is going to run you another $100 for 4 bulbs.
Buy cheap, buy often. I have learned to do it right the first time.