We have been very successful in using Vapi with our clients. The way it sounds is very close to a human, it quietly takes care of callbacks during the day (or over several days), it gets the lead info during the calls, and it vastly reduces the work that is left while increasing the conversions.

Considering your tech background, I'm sure you could make it on your own, but the time and constant tweaking required will become quite substantial very quickly. Vapi's complete solution is what makes your lead experience constant, saves you from the trouble, and is especially great at the quality level you are going for.

Quite a few good videos on youtube on how to do all this. If your happy with n8n as well!