Where can I find different equestris varieties?
 

After a long hiatus from actively acquiring new orchids, I've been reinvigorated to clean up my tropical greenhouse and try and replace some of the plants i've lost over the years.

Any advice on where I can get seedlings/keiki's of equestris? I'm looking for alba, aurea and pink forms. If you know where I should look (or have some keiki's you want to get rid of), please let me know

I suggest you take a look at online vendors.
Here's one
Phal. equestris var. aurea 'Montclair' AM/AOS / Orchids.com

Here's another. FWIW Peter has great plants.

Phalaenopsis equestris var alba 'Chin Yo' [cy45] - $28.00 : Big Leaf Orchids, Fragrant and Novelty Phalaenopsis

If it's the same in the US as in Europe, it's hard to find any one place that sells several types of equestris. Aside from the suggestions already mentioned above, you can check out the vendor feedback forum for recommended nurseries, and look to see what sort of equestris plants they may have.
I checked a few other sites, and Hausermann has equestris var coerulea.
Don't hesitate to email or call nurseries, they may have other types but not in high enough numbers to list online.