hi its good 2 x A350w for my 40x24x24? sps mainly? ora 2 A350 and 1 A350W at center?

I definitely would not mix and match the wide and regulars. Pick one style and stick with it. With regards to if 2 is enough for your 120 I would suggest browsing this thread a little more since it's been discussed many times.
Ive never seen those white plastic/metal pieces that allows the Kessils to be pointed straight down from the angle there placed at. Would be cooler if they were black to match but they're pretty cool, anyone using them?
Over a 40B? I don't think so. One 150 was perfect for my 12 gallon cube. I'd go with Qty (2) 350s.2 a150s work?