Ortofon Super OM40 compliance and tonearm match (I'm getting crazy with the numbers)

Keep in mind that the effective mass of the tonearm should include the weight of the headshell, the mounting screws, and of the cartridge body itself. Given that that is the case, I find your estimate of the effective mass of 7.5 g to be probably too low, and probably representing the mass only of the arm wand or perhaps the arm plus the standard headshell. Also, you need the vertical compliance of the cartridge not the lateral. All of that said, it seems you want to mate a high compliance cartridge with a rather lightweight tonearm, and that should work with no worries about the math.

Thanks Lewn.
I'm planning also to purchase a SME 3009 serie III. I believe this is a lightweight tonearm too, for what I read around. So, the OM40 super will be a good fit too right?

The SME III will be a favourable match, just confirm which 
of the 2 CA-1 removable arm tubes you end up with as the
alignments are different if using SME alignment  guides.

Last the OEM phono cables if supplied are pre loaded for additional
capacitance internally. 

Ho, good to know, I was not aware about that
thanks