Coralife and Seaclone skimmers would not be adequate for any normal stocking levels on a 150g. In my experience the Coralife are very touchy, prone to overflowing, and easily broken. I work at a LFS so I have had numerous complaints and issues about Coralife skimmers.
If you want a HOB Skimmer, octopus makes some of the best ones for the money. You would need two of them. Any reason why you haven't considered an internal Skimmer? Tunze makes some excellent ones and their footprint is often less than an overflow box. They even have models with filtration built in so you have everything taken care of without any other odds and ends cluttering up your tank.