Very good points from aliEnRIK. If it's a choice between the two, the Carnival is presently £2 or £3 cheaper and you may as well base your decision on that. It is very thick, though easy to strip and work with.
Whatever you go for, keep the speaker cable you presently have. Then test it against your new purchase (when "burned in" if you consider that necessary). You will then know whether to spend money on cables again or not.