Is Rail Europe normally the best option for travel b/w these or does France have a better rail alternative?
Rail Europe is one of the worst places to look for train travel or buy tickets.
Use the official French train site:
Or download the SNCF app (SNCF Connect) which is what I use.
Not only is SNCF the best place to buy these tickets, they are the company that actually operates the trains. But be careful about trying to book to early. They may not have the schedule for all trains (including the direct, non-stops) until a few month ahead of time.