first off, you don't need a good light. just avoid incandescent bulbs. if you do buy or have an incandescent hood, replace it with a medium cfl. you certainly don't need a T5HO or power compact on a 5 gallon. just aim for a color spectrum of 5000K-6500K for best plant growth and realistic colors.of course if you wanted to go different, that's fine too. I'll bet some of the pearl shrimp would look cool under 10,000K lights.
secondly, buy whatever shrimp you want. why would you buy what someone else wants you to have? go to e-bay and aquabid and do a search for shrimp, research the ones you find that YOU want and then when you find ones that you can well care for, order them.
as far as the substrate, get what you want. shrimp will survive equally well on sand, gravel, or ceramic covered quartz. some people even have moss as a substrate.
goto google image search and type in shrimp tank, you'll get hundreds of pictures to look at and decide which look you like better.
