@ Beardown
For this style you need really stretchy strains or you will be disapointed, trust me I've been there. That RKS sounds like a contender but you may have to defoliate if it gets too bushy. The Viper sounds more like the Blueberry or Godbud that I tried to grow this way and was not happy with the result. I hear lots of people saying you need a 50/50 hybrid for best results but I haven't run one yet, maybe on my next order.
My yields weren't that great after I switched to the 400w with light rail, 10oz first run, 8oz second run. The first I had one strain that was not at all suited for this style (God), the second I let my canopy get way out of control and had too much larf. Both during the winter with very cold lights out temps (50F).
The summer before I got 8 oz with a 250w, no light rail, no training, and a really stretchy strain. So now I've got those warmer lights out temps back and I ditched the light rail so we'll see. Basically I won't be happy till I hit at least 12oz which should be totally doable.