Which turntable? Pro-Ject or VPI?

The VPI is a better long term investment.

Honestly I am not sure you could wrong with either. But for me I also look at the perspective of (if buying new) who I want to give my hard earned money to. Having been in the industry years ago I have really grown fond of the VPI family and respect their culture and how they treat their customers. Not that Sumiko and the Project group don’t but just my personal bias that would lean me towards VPI. 
For what it’s worth. 

VPI.  

My uncle Moshe told me when choosing between the best house in the cheap neighborhood and the cheapest house in the best neighborhood, pick the house in the best neighborhood, the cheapest house in the best neighborhood is always the better choice in the long run.  He’s proved right.

I see the same working here.

VPI and I am biased since I have the HW40 direct drive. 

Neither.

Either

TT with a tonearm with removable headshell

or

No Tonearm, add arm with removable headshell

or

TT that allows a 2nd Tonearm, 

1st Tonearm: EASY Arm Height Adjustment