Social Media, SEO, Direct Mail, Cold Calling, etc.) have you found to be most successful in your virtual wholesaling business? 

As in, you are not going to list them or wholesale them (if you promise you are buying them).Then of course no matter what you do you make sure your SEO is on point.

There's driving for dollars, direct mail, text message marketing, SEO, cold calling and others.

If so, are you doing any ppc or SEO marketing?

Does anyone have a good company that will develop my website and help me get leads organically through SEO?

Both their financing and SEO power are better than you can ever be. 

Recently been introduced to the idea of real estate wholesaling.  With the Covid pandemic I am wanting to explore ways to wholesale using the internet as my first contact.. ie they want to sell, my company comes up on...

DONE.Wholesalers are often too eager to get a deal they will sign anything they can get.You WILL fail.The #1 hurdle with wholesaling and REI in general is finding deeply discounted properties that are off market, like clockwork, on demand and fully automated... at low cost.Look into SEO and you will be all set!

I would recommend becoming the "authority" in your market with a combination of SEO, PPC/Facebook Ads & social media marketing.

You may also consider learning a computer trade (like SEO) where you can one day benefit from by generating your own leads.