In any case, you need a power supply that delivers 2A@12V plus 2A@5V. If you buy a Sata/USB adapter, make sure it comes with such a power supply.
I own a Delock 61391 which comes with such a PSU and all cables and adapters needed.
As for the Via controller: Via Sata controllers are not famous for their compatibility with optical drives. Controllers with Silicon Image chipsets should be preferred. But as already mentioned, you need additional power.
Also, I'm wondering how the stated speed will be affected because of the way I'm connecting it to my laptop.
With USB connected drives, the Sata/USB controllers as well as the USB controller of the computer do affect the speed of the drive at least. I would not expect much more than 12x, with some luck you may also obtain 16x max.