I've split your post from the FAQ thread, as that's just a guide really.
First thing to do is decide on your budget, then do a bit of research and find out what you can get for your money. Once you've done that, if you're still not sure, post up with what the different options are that you've got and get some opinions.
As for a safety factor, so long as you get a set from a recognised manufacturer and they're fitted correctly, it's not even an issue.