this is nice.
If you don't want to go that large you can do something like
this scaled to your needs.
As far as lights if you do not want to go HPS there are alternatives such as T5/T5HO T8 T12 fluorescent. Keep in mind some alternatives are not as good as others. Alot of people are stuck on t5ho right now when in fact the luminous efficacy is not as good as the standard t5 which is cheaper. The 28w and 35w versions produces 104 lumens per watt. While this may not be on par with HPS which at 600w(most efficient) is around 158 lumens per watt.
CFL's only do around 60-70 lpw at MOST.... CFL's and t5/t5ho t8 t12 all produce low heat signatures comparitively to HPS. If you are looking at other lighting my suggestion is straight t5 to get the most bang for your buck(yes you will need ALOT of them). My plan would be taking about 2/3 of lumens that a HPS produces(600w produces around 90-95k lumens) so lets say 60-70k lumens of t5. HPS will lose those lumens when placed over 18 inches away to cover the plants(refer
here to calculate exact numbers related to inverse square law of light distribution), however t5 can pretty much touch the leaves.
Make sure you get 6500 kelvin lights as well as 2700 kelvin lights so the plant can properly utilize the light it needs at given moment.
I would also look into reptile lights that are around 280-320 nm in wavelength to utilize while flowering. Their function would be to stress the plant to cause it to produce THC as a defense mechanism thereby giving you a stronger and smoother smoke.
-potlike