Boulevard doesn't even use a Saison yeast for their Tank 7, although a great beer, it's also not very saisonish.

But their Brett Saison is among my favorites.
If you want to stick with WYeast, WY3724 is very nice, but tends to stall high (1.020s) and then takes 3-6 weeks to finish out nice and low with some TLC (or harsh language). WY3726 (a PC item) is a great replacement for 3724 without having the mid life crisis, but not available unless it's in their PC release cycle.
On their PC list right now is
Wyeast 3031-PC Saison-Brett Blend. Now that wakes me up. You'll probably got to special order it through your brew store, as most never stock the great PC stuff. It's available till the end of August, so you need to hurry. Or mail order, but with the hot weather that can be a real toss up.
I've been using ECY08, Saison Brasserie the past year and more recently ECY03, the (Fantôme) Bretted version of that. I really love both, with a special nod to the 03 of course, giving it ample time. I ferment these lowish and slowish. It's like pineapple juice that way.
There are plenty others from other (liquid) yeast suppliers, we have a great choice now. Even Belle Saison (dry) is quite respectable, and loves it hot (up to 90-95F!).