ATI, Geisman, Current are all good lamps and I'm sure that you will find most everyone on this board who use t5's have particular color favorites of each brand and do the same as I do and mix and match lamps from different brands. ie: Geisman 12k, ATI super blue, ATI true actinic etc. I will say I have found the best life from Geisman lamps. If you find any ice cap lamps (they would be old stock) beware their lamps were built to be used with their ice cap ballasts so as to overdrive the lamp and if you don't get that overdrive the lamp won't reach it's proper color spectrum
I use the wave points, they are fairly cheap, and you can find them locally. I have a nice combo on my 210. 4x blue wave, 2x reef wave, 2x coral wave, 2x sun wave, and 2x tropical wave.
Ato purple is more red. Kz Fiji is purple . Geismann actually cost more than ATI for be. Relatively same par, ati being slightly higher. Kz is insane, both in par and price.