Id go for queen bees first personally. And then when you have one of them, try and shoot for BELs. Or spider/pastel BEL's. A pastel BEL would be even whiter i would think!
Idk, as nice as an all white snake is, i personally just prefer a lil bit of pattern somewhere. Like the yellow splotches on BlackEL's. Or high white pieds. Stuff like that. Just personal preference though i guess. Go with whatever YOU wanna make first more doolittle!