What led lights to buy?

[Aquattro]

Most LED will grow SPS, as long as you have enough of them. Kessils make nice spots, AI Sol and Radions are nice pendants, Vertex is known as top of the line.
Affordable is a subjective phrase. I just bought 6 x AI sol, cost me about 2700.00 after taxes and controller. Some people buy that many Radions, runs them about 5000+. Vertex 260 line are on sale lots of places this month, a 4' fixture will run around 3000ish. If you go pendants (AI or Radion) you'll need at least 3, probably 4 units. Kessils you'll have to look up, don't know what they go for.
Reef Brite has some fixtures that are more affordable for lots of people, sold by Reef Supplies, one of our sponsors.
If you're handy, you can DIY some lights, Modular LED has all the bits you'd need. You'll save some money, spend some time.

Sorry, not an easy question you've asked