Curious how you would define 'rare'. I usually buy my yeast from MoreWine. They have a pretty expansive selection, but I'm not sure I'd call any of them rare.
Favorites include BM4X4, RC212, RP15, and D254 for reds; and QA23, BA11 and K1V-1116 for white wines.
I could have written the exact same thing that Jim above me did. That's my go to yeast place and except for RC212 I like and use all of those. Just ordered D254 for my Chilean reds last week.
Joining the club and adding BDX, AMH, Syrah, R56 (Vintner's Harvest), Clos, GRE, 71B, D80, Rhone 4600, VRB, 58W3, Cotes de Blanc and this fall will be trying Avante and Fermentis HD S135.
Yeasts are not really rare. Suppliers like MoreWine, Lodi Wine Labs, and your local home brew shop will likely have 10 or more red wine yeasts on hand. MoreWine is an extremely reliable supplier with a very broad selection. A bit later this year, Lodi Wine Labs will have a nearly comprehensive yeast selection anticipating the fall harvest.
But if you're new to wine making, I'd just use one reliable yeast. Avante is very reliable for several reasons, and you can tell from what others have said, lots of success with multiple different yeasts. I'll toss out another that was a great no issue Red wine yeast for me: ICV D-21. Doesn't get a lot of press here, but does a great job. I've also used D254, and Pasture Red. Both fine. But Avante is my go to.
To be honest, I'd invest more time and energy in sanitation and avoiding oxidation, than what yeast to use, since nearly any commercial yeast is going to do the job. I've posted a couple of links to MoreWine the first is to purchase yeast and the second is their yeast recommendations: