Buying a running west

I'm training my way to the ultras. This week was my first 23 km run and I didn't carried any water. I ran back home at like ~11 km, had some gummy bears and like 500 ml of water but it caused a little discomfort. Like I just poured down the water, stuffed down the gummies and ran on. So I want to invest into a running vest/backpack for my longer trainings and possible self-ran marathon. What are your advices? I'm not yet like a runner looking weight, and I really don't like people seeing me in a vest. I feel the discomfort that wearing the vest would make me feel like. I don't really bother people watching me while run. I don't really bother with people any ways in my life on other subjects. I don't really care about other people's opinion any other ways in my life.

I just want to know other runners opinion of how much of a distance is a running vest "legit"? I can run 10-12k no problem without any water or carb, but over that I feel like I should carry some.

What vest is a good golden-middle class vest for a male of 30 years old? I'm about 178 cm tall and 95 kg's.

Also how do you feel yourself in a vest?

I'm also cycling, so it would be good if I could use it for longer cyclings too.