I did not include exposure protection in my answer because you said you already owned a wet suit. Exposure protection is very important because you need to enjoy your dive, no matter what type of gear you have. Since you already own a wet suit, I would buy in this order (or close to this order):
1. Regulators. I like Scubapro MK25/S600 or MK25/D400 (if you can find a D400).
2. BCD. I prefer the rear inflator style like the Scubapro NightHawk for recreational diving. Backplate/wings are good for more technical diving, or as a close runner up to the NightHawk, depending on your style of diving. Most will argue for the backplate/wing setup first, which is also a great way to go.
3. Computer. Once you are comfortable with using your basic dive tables.
4. Tanks. I prefer steel 100 c.f. approved for Nitrox.
5. Other misc. gear to make diving more safe, interesting and fun. Try not to do to much "multi-tasking" underwater. It can get you in to trouble.
If you buy good gear from the start, it will last you for a very long time if you care for it and have it serviced. I definitely would not lower my standards when choosing life support gear, especially regulators. You can do a search in Regulators and learn a lot about the different types out there. Use what is comfortable and works for you, regardless of the opinions you will read here. These are just my broad-based suggestions, without knowing fully what kind of diving you do, and in what environment.
Good luck and safe diving!