For lean gains, Tbol and var would be similar but I think the biggest depending factor would be diet. I would go with var over Tbol, just because I have seeon some more intense numbers on lab work after taking Tbol, than taking Var. Overall, best for gains maybe primo, because you can run it for longer. You can easily run Primo for 12 wks, even 16 wks for the more experienced user. With any of these, I would use test as the base of the cycle, at least taking 250mg of a long acting test, split into 2 shots a wk. Here is how I would dose the 3 compounds you are interested in, in order of what I would use

Test and adex along with either :

Primo 400mg EW, split into at least 2 shots per wk

Var, 50mg ED for no more than 8 wks

Tbol, 50mg for 6 wks, in a longer cycle, continuing the test for another 6 wks,

Of course, you'll want to do a PCT after the cycle