So far, my favourite mix has to be:
Primary:
Euston AR
COGA Scope
Front Grip
Four Vent Brake
High Cap Mag
This turns the Euston into a highly efficient mid-long range battle rifle. Very accurate and has a lot of punch. The ROF is high enough to burst in a jam, and if you place your shots well the magazine can last a good while.
Secondary:
Carb-9 SMG
d-Flex Red Dot
Front Grip
Down-Vent Brake
High Cap Mag
Generic SMG tweaking I guess. Serves as a great back-up to the more pin-point Euston for CQC. The extra accuracy of the Front Grip and the Red Dot make this a a beast to spray with. Bursting with it and you can emulate a AR style play if you’re out of primary ammo too.
How about you guys? I can’t imagine this will vary too much as some of the weapons are absolutely redundant… but it would be cool to see what people’s preferences are so far.