Howdy and welcome to CR. As far as lighting, you can upgrade to a pendant halide if you really want sps, but your current lighting should suffice for just about any euphyllia(frog spawn, hammer, etc) as well as some brains and candies. SB well that's just an opinion of what is better. I've been mixing 3 cups per 5 gl water and all is well. As for bottled... get the ro/di. If you have a walmart near by, you can usually get it for about 30-40 cents per gallon with your own container. IMO, add your LR and possibly a few cleaners and you should be ok for now.

Jason