Try the AM or Current 10000K and 6500 GE Starcoats. Thats what I'm going to do next as the Plantas are a bit dimmer, mine from the getgo. I think we'll be seeing more choices before to long since so many fixtures (beyond aquaria) are going T5. BTW, Bill Harada posted that the GEs were quite a bit brighter than the Giesemanns at least at first. I haven't heard over the long haul. FWIW, my plants really like the Planta 10000k combo. But I think they stretch a bit since its not as bright and reds are harder to pull out in the plants too.
Three Tanks...Eheim 2128 & XP3-90G, Eheim 2128-65G, Eheim 2232-25G.... Tek 4x54 watt T5-90G, Aqualight 96watt PC 65G low tech, 65 watt Aqualight-25G.... Hydors-90G & 65G ... Flourite in 90, 65, & 25 Gallons, .... Auto Water Change/Auto dosing on 90 & 65 gallon..... AGA member......