DO NOT REMOVE THE HEATSINK FROM A VANTEC

From the purely practical side it would be a pain in the arse as it is attached with a good few dozen bolts and secondly it will dramatically reduce the current handling capability of the controller. I also wouldn't advise a vantec as your first speed controller as they are relatively delicate or rather they don't handle being connected up wrong well

O and the issue on tax is a bit of a mute point as you are paying tax on everything you buy in the UK anyway