I would say a more powerful amplifier would be preferable, but the main thing is to not run it at a level where distortion can be heard. Give your existing 30W amplifier a try and see if it suits your needs.
It's easier to damage a speaker with a low powered amplifier that is clipping (ie driving DC into the speaker) than it is with a power amplifier which is rated higher than the speaker it is driving.
To be honest the wattage values of speakers and amplifiers can be very misleading. The sensitivity figure of a speaker is just as important as its wattage. Some people think that the wattage figure tells you how loud a speaker will go - it doesn't, it tells you how much power it can withstand.
But remember, distortion is your enemy.