i could never get my triceps to work on close grip bench, unless my hands were so close that if fucked my hands/wrists.... but then one day i got high before i worked otu and i instantly realised the way to use triceps instead of chest/shoulders....for me, hand grip is inside the shoulders, but outside the pecs. right in the sweet spot, then you low the bar down while rubbing the inside of your tris up against your side/lats... and then on the way i really focuz on pushing up and out on my elbows with my triceps...while keeping my arm path of motion tucked in close to my sides... that really helsp..
as far as the weight goes, it depends, i can go as hevay as 275 or as light as 135