I used the cheapest stuff they had at radioshock for my current in progress build and on my previous build. It works fine on my current rig running 26 A through a 40 A SSR. If you're closer to the load current rating for your SSR it might be worth the extra $ to get the good stuff, but at that point you will see more benefit from going with larger heatsinks or forced air cooling.
The power to tax, once conceded, has no limits; it contains until it destroys. I was not joking when I told them to dig into their own pouches. It may not be possible to do away with government — sometimes I think that government is an inescapable disease of human beings. But it may be possible to keep it small and starved and inoffensive — and can you think of a better way than by requiring the governors themselves to pay the costs of their antisocial hobby?
R. A. Heinlein