M65 Pro? i have a few actually and i love them. 

Oof that looks like barf

Logitech G403 (wired) for $60 and the Logitech G703 (basically a wireless G403 w/ wired fallback) for $110 are quite similar to the G303 in terms of the shape/grip.  I have a wired G203 that works, looks, and feels great, and you can get one of those for like $30.

The M65 Pro is an acquired aesthetic taste, but my dad has one and I've never gotten used to a mouse so quickly in my life.

The G303 has a really weird shape, oof.

How big are your hands (measured as pictured)? What came to mind first was the razer viper mini (which is wired only), but it's a different shape though overall very close in size.

My hand is 18.5cm by 9.5cm

And the G303 isn't too small for you?

My hands are similar in size, and I use a viper ultimate. However, I am left handed, so i need the ambi shape.

If you like the G303 size, here you go- https://www.amazon.com/Razer-Viper-Ultralight-Gaming-Mouse/dp/B084RPZD6T

If you want a larger mouse of a similar shape- https://www.amazon.com/Razer-Viper-Ultralight-Gaming-Mouse/dp/B07TT8G59J?th=1

If you want to spring for wireless (much more expensive)- https://www.amazon.com/Razer-Viper-Ultralight-Gaming-Mouse/dp/B08565C5BB?th=1

The G303 is a small mouse for my hand size, but I've been using it for near 5 years and I like it. I'll take a look. Idk how I feel about buying Razor products tho  

@DrMacintosh Stay away from Razer wireless.  Period.  That Atheris was awful...

@Techstorm970 Using a viper ultimate as we speak, best mouse I've ever used. 100x better than my old g903 or gpro.

All up to opinion and experience though. I'll never be buying logi again

Did Razor fix the requirement to have their software open to have RGB control? 

I have the Basilisk Ultimate, it's pretty neat and has the wired/wireless option like my old g703.  Ergonomics depend on your hand though, and it's a little heavier than most gAmEr mice.