I operate a forum and currently use VB, but They have had a ton of customer service issues the past year and the new 4.0 they are selling was rushed out and has significant bugs.
I will not be upgrading to the 4.0 version of VB. When the 3.8 version reaches end-of-life, I will be jumping to IBP. They are feature rich and priced well with VB. Take a look at all of your options before, jumping to VB.
My former reseller host offered all 3, I played with them all but found Softaculous to be my favorite. I believe Softaculous also offers WHMCS? Is this an option HawkHost is looking into?