We're a bit biased on here so most everyone I hope here would recommend KH to you. Assuming you're currently on cPanel the migration should be a very quick and easy process. Looking at WiredTree SSD-4 is likely the closest to their ssd-4000 package. I don't have multiple VPS' just a Dedicated server so I can't speak for that discount structure that KH offers, but seems pretty straight forward. Depending on your needs, maybe you could do better getting a dedicated server over multiple VPS servers.