This has been stated 100,000 times before, BUT buying a completed upper in the caliber you want and then building your own lower makes a lot of first time builders happy.
I told the new me,
"Meet me at the bus station and hold a sign that reads: 'Today is the first day of the rest of your life.'"
But the old me met me with a sign that read: "Welcome back."
Who you are is not a function of where you are. -Off Minor