god i love the 8bitdo n64 controller, wish they'd make a solid red yellow and blue version

Gotta try out the Mod Retro Controller

About the 8BitDo controller, the gray one with buttons coloured like on official N64 controllers is something they added latter. At first, you only had the choice between a fully white one or a fully black one. (I think they added more colours since, but they may be collectors.)
Also, you have brands making bluetooth receptor for N64, (including 8BitDo, but that's a recent development) so with one you should be able to use the bluetooth 8BitDo controller on an official console. (Also, the Analog64 support said bluetooth version of the 8BitDo controller out of the box.)

As for the clickable thumb-stick, it's more because you can't find the mechanic part for a non-clickable one anymore than anything else. That said, if you plug it on PC, you should be able to use the fact its clickable.

Could you do a full review of the Brawler64 Pro? Testing how the analog stick feels in different games (walking in Mario 64, aiming in goldeneye, steering in racing games like MK64, etc) ?