Personally I just switched to TKL keyboards (no numpad). While I did use it occasionally, it wasn't often enough to feel inconvenienced without it... All the buttons are still there after all, and if I'm already at home row, it isn't any slower.
May be worth considering too, especially if you're looking for a good keyboard with eg magnetic switches vs shitty rubberdome
I went to https://www.keyboardco.com/ and searched for left-handed and the keyboard in the photo popped up, as well as a bunch of weirder and wonderfuler ones.
Yeah I would suggest you stick some wood on your left side of your current keyboard, for a few days to see if you can adapt... I always used that space as a resting place, so having it occupied totally broke my flow.
(If I needed a numpad I would have it standing alone.. those are easy to find)
I've been looking and looking, but the best I can find is using a narrow keyboard with a separate number-pad only keyboard on the left. I'm in the US.
(It's better for your right shoulder to keep the mouse closer to your body like in the picture.)