Disclaimer: feel free to flame me if you see anything heinous or disgustingly wrong, I'm pretty sure I don't know much more than OP, and I've been too afraid to start chatting for help given my initial experience learning the hobby through r/MK after watching popular YouTube streamers, and finally finding Geekhack through Taeha/KristoferYee. I've only physically owned a Ducky O2M w/Box Whites and a gamer-brand linear board for about a year, and am just now getting into purchasing parts from group buys to eventually build a custom board myself. Still looking to try to get into the NK65 batch releasing for Black Friday, or a KBD67 Lite or Tofu65 otherwise for my first build, along with Zilents v2 to satisfy my family cries from clickies on my Ducky, and the live GMK Honor keycap set for the future.
The Venus 60% seems to be a competitor for the Ducky Mecha Mini (Aluminum version for One 2 Mini), and it seems like a really strong choice given the bigger selection of switch options outside of standard Cherry MX (I found aftermarket kailh (cherry MX clone type) switch choices on Amazon from the US, HK Gaming main website was out of stock and I don't know the situation for availability in the UK). Unless I missed something earlier in the thread, it seems like you've settled on a 60% board, however, if you haven't, be sure to take into consideration what keys you'll be missing. Since this will be your first board AFAIK, you're likely going from a full-size board and are going to have to sacrifice actual keys for the smaller form factor: including the numbpad, numerous function keys, and of course arrow keys (some 60% layouts have arrow keys instead of certain bottom-right function keys, but the boards mentioned including the GMMK have no physical arrow keys) in favor of layers on the remaining keys that will make up the 60% board. Many people here will discourage the MX Brown suggestion you threw out, but if you haven't tried any mechanical switches before (linear, tactile, clicky), they are at the end of the day still an extremely popular switch that you can use as a baseline reference to discuss alternatives in the future if you don't end up liking them, many people have tried cherry browns, and many still use them. I've had the chance of using a board with browns, and I found them much more enjoyable to use than a membrane board, albeit less tactile than I'd like. They felt close to linear switches when not just pressing a single key to find the slight "tactile" bump, but you can do a lot worse for your first switch. Anyways, I'm happy to see that you were willing to stick yourself out (unlike how I started, INFP here who didn't want to start up fights with my lack of knowledge) and dive right into your first board, given that there's so much to learn about when starting out, and I'm sure you'll enjoy your first board.