i'm not sure whoever advised you the amp should be more powerful then the speakers rated power handling was correct, or maybe you mis-interpreted the advise. a more powerful amp will have better control of your speakers then a weedy one. i think pushing a weedy amp past its limits, so it starts hardening/distorting, is more likely to break speakers then feeding them with a bit too much power. the issue with too much power could be the cones running out of travel, although that is just a guess.
do you listen at full volume very often? i think you should be able to let your ears guide you, as the sound should start to change if your pushing something too hard.
so, assuming i'm not talking rubbish (which is possible), i think the better suited speakers will be the ones you prefer the sound of.
i've just re-read your post, theoretically, the better suited is the 140 watt version as your amp is within their rated power limits.