It's perfectly allright to buy in North America and take it to France.
The MBP DVD player will play DVDs encoded both ways - the issue with NTSC v PAL is not the DVD Player (SuperDrive) - but the display - an NTSC or PAL television cares as it is a question of resolution and phasing, a computer monitor can cope with either as it is not set to either standard - so this is not a problem - it can be a problem with camcorders though.
BUT.
Commercial DVDs are coded for the region in which they are sold. The first time you play a DVD, the computer asks which region you wish to set to. Once set, it will only play DVDs coded for that region or no region or all regions. So if you insert a US DVD, it will ask you to set the region code. If you select region 1 you can play that dvd. If you then insert a PAL dvd from Europe it will ask if you wish to change the region. If you decline the region stays as before and the dvd will not play - if you accept, it changes and plays. This process can only happen 5 times before it is locked. Once locked only Apple can unlock it and they can only unlock it 5 times.
So if you buy the machine and take it to France, you will be fine if you do not start the DVD player application or Front Row until you get there. Then insert a European DVD and set the region.
I hope that helps. It is a way of preventing global trading of DVDs - and the same thing would happen if you bought a MacBook Pro in France also, so there is no reason to let that stop you from buying the machine.
I hope that helps.
Best of luck.