What you’ve listed there is pretty much the gold standard. If you find yourself needing more juice later, just slap another 8GB of RAM in there and you're golden.
Four VMs? And running SQL Server at the same time? Don't even think about going under 12GB of RAM, or you're gonna kill it... It's a gaming-grade mobile processor, so you're fine there. Everything else looks alright, but seriously, bump that RAM up to 12GB if you want to handle that kind of load.