Hi!
I trained with Xen Tan, but didnt do it with the company i did it at The carlton institute,
HONESTLY,
dont stress yourself about it, i learnt with xen tan and have since used fake bake, xen tan, tantrick, LA and currently using sienna x
They teach you the basics etc, but i now spray completely differently to how i was taught, you get your own rhythm once you get good at it and youll do it how your comfortable.
I prefer LA and Sienna X out of all of them, and i hear Sienna offer great training but id say look for price, i payed about £150 if i remember and some places are alot cheaper but you learn the same basics.
If im honest id say go with an academy so you get their diploma or whatever qualification you get in spray tanning but so its not hooked to one brand so you can play around and see what brands you prefer!
hope this helps x