Soldered Female Header Pins

I’m very new to PCB creations, but i need one for a scientific project I’m doing, and figured I could have a shot at it myself.

Right now I have 10 of these, and they have thru-holes on which I solder female header pins myself. This enables me to take off my components again when I want to swap a PCB. However, I’m planning to get 100 of these PCBs made in the future, and it would become time-consuming for me to manually solder the pins for each of them.

Is there any way to have a PCB like this made with female header pins pre-soldered on it?

(for the record; feel free to leave any feedback about my PCB. It’s not finished yet (hence the large unused space on the right) but should be a good example of what I’m working on.

While I have never done it, there are board houses that will also do assembly for an additional fee. For 100 boards I expect there won’t be a problem. Perhaps someone who has had boards assembled can recommend a vendor? The board looks fine to me and shouldn’t be an issue.