The wires that run to the taillights are very thin, I doubt whether they can cope with the increased load! I think that there is a big risk in melting down your wire harness before the bulb will even melt down the lenses of the taillights.
I don't know how the plastic rear window in your soft top is, but mine is completely blind. I normally push the brake a little to get more light behind me when I am reversing...that helps as well.
The link you provided us with, mentions something about increased heat and that line is written in red...beware!
with a minor 600+k