EDIT; After realising some major points, I have changed the tone of the topic to instead suggest a reduction in the new maluses, but also to remove the bonus effect of jackets, to force sneak never to go over 200.
So for armors I would suggest;
Jacket and coat variants = No modifier
Leather armor variants = -5% to sneak
Bluesuit = -10% sneak
Support CA = -15% sneak
Combat Armor = -25% sneak
Metal Armor = -50% sneak
Power armor = -95% sneak
While weapons would be as follows;
Pistols/SMG/One handed melee (not including powerfist variants) = No modifier.
Rifles/basic shotguns/two handed melee/power fist variants = -5% Sneak while standing or walking, -5% additional sneak while running.
LMG/Heavy shotguns/GL/Flamer = -10% Sneak while standing or walking, -10% additional sneak while running.
Anything bigger = -25% Sneak while standing or walking -25% additional sneak while running.
Also displaying these penalties somehow, whether in the item description, or by showing a physical reduction in the character sheet when worn/equipped would be helpful to noobs, and forgetful types like myself