Neotat stroke & spring suggestion

[Heath]

I'm getting a Neotat Vivace. I'm not looking for a liner, just a versatile gray shade/color packer. I've also never owned a Neotat before.

I was wanting spring suggestion (red: hard, silver: regular/soft) and stroke suggestion. I was thinking of going with a 3.5 stroke with the red spring solely because it will pack color but easily gray shade really smooth. I was also thinking of the same spring but with the 4.2...but feel it might limit my gray shading flexibility.

I did own a Blitz that I loved, it was a 3.5 stroke and was very flexible...and my current Kubin mini Cranker 3.5 is very versatile too...