Hiring the right Sales guy for IT Services Company

guys, I am more of a technical guy who has a startup providing Microsoft IT Services in Wisconsin. I am very strong technically but very weak from sales perspective. Generating leads is something that i do from speaking at conferences, having booth or word of mouth and my partner( call him the sales guy) follow-up with the leads. Every time i have tried to hire a sales guy to generate me business or leads it has been a disaster. below is the history.

a. Sales guy 1 ; 47 y old : quits after 3 months. he was not able to generate any leads.

b. Sales guy 2 : fresher, hired him when Covid hit, he was with us for 1 year never generated even a single lead. its always been i am trying to reach them etc.

c. Offshore Cold callers : they research companies and call them: i have had a guy for 1.5y but i was never able to get a single new lead.

Every time i put an ad in LinkedIn or monster for a sales guy, either they are demanding salaries which is 6 digits with minimal background or they don’t want to work with a small company. Me and my partner are always busy with stuff and don’t have time to baby sit sales guys. Where are we going wrong? How & where to hire a business development guy who can generate leads for me.