I bought a USB modem from SFR a few years ago, works perfect.
Searched the sfr site, and they offer a data stick for 39 € (
http://www.sfr.fr/mobile/cles-pc-tablettes-offres/cle-internet-cle-internet-3g/les-offres-internet-pour-cle-3g-?vue=0002f9&type_offre=sfrlacarte&toutes-les-offres=&offres_pop=sfrlacarte#f|type_offre=SANS_ABONNEMENT). 3 hours internet is included, afterwards you load it up with pre-paid cards (pass internet 3G). In the past years those passes were valid for a certain amount of hours. Seems like they've changed it now to a certain amount of data, up onto 1 Gb for 35 euros (
http://www.sfr.fr/mobile/offres-internet-mobile-cle-internet-3g-detail?vue=0002tp&toutes-les-offres=&gammeSeoName=pass_internet_3g_plus&op=002qni&engagement=002qng&pta=0028hc).
If you're only streaming live timing, I guess you should get quite far with 1 Gb.
There's more info on this site :
www.sfr.fr (only in French) and
or here
http://international-travellers.sfr.fr/en/index.jsp (couldn't find anything about the data stick).