I will chime in here. Mostly due to the price (used) I picked up the redsea 130d. All the stock equipment, heater and skimmer in particular, are crap. I run a sump with an overflow kit and a tunze 9002, in the sump, as my skimmer.
Ive gotten the tank dialed in and I really like it. I do have some questions for you. Can you run an open top? Meaning that a big reason why I looked into the biocube and redsea was the look and the fact that they have tight hoods that can be modified.
If you can run an open top and can afford a really nice t5 fixture I would go that route. Find a nice tank and stand and spend your money on a good fixture. I wouldnt reccommend these tanks to someone thats not buying used with plans to modify and have fun with, if that makes sense.
Also, I would never buy one new. Way too expensive in my opinion. But again I love mine now, its been alot of fun making mods and it looks freakin awesome in my opinion. Very Clean. Feel free to ask any questions you have about the redsea. Good luck