I would run a test with Search Ads in Google Adwords, Facebook Ads and LinkedIn Ads to see which one perform the best. That would be my short term!
Then, Content Marketing (Blog), Social Media, Email Marketing and some Display Advertizing.
I've worked with 2 companies like yours and these channels worked for them!
I usually work on a weekly meeting (1 hour) basis and it usually takes between 2 and 3 months to have an integrated digital strategy up and running!

Do you have a website where I can see the services that you offer? Without knowing much about your company Google AdWords may be a good platform for you to advertising on, but I would have to know more about your business to give a better answer.

Instead of focusing on what your company does, focus on where your customers are. For example, if you want to target real estate agents for your web development services, hang out in real estate forums and where real estate professionals are already networking.

The best channel is where your prospects naturally go.

I'm happy to help you further! Good luck

Your audience partly overlaps with mine. When someone purchases a domain name, they will often (though not always) turn next toward developing that brand / property as a website. Sometimes that's a simple WordPress site; but occasionally the objectives are more ambitious, requiring extra code or even a custom-built platform.

Certain channels focus on this moment of "project conception". Anyone without a tech team will need to hire somebody. So you may want to put some thought into WHERE people go when they are passing through this phase.