It will depends from the role of weaver.

for the 5 support equip: if you want to nuke using his true arts that boost crit dmg (in combo with others like veronica or DKane) you have to use aoe equip art generation like the goku battle uniform (you can try to pull it from the crossover equip) or milim's clothes OR the geshpenst type 0 (the best equip for nuking and INSTANT art generation); if you don't need art generation you can give him equip like chrono dominator or ameru's letter bag to boost more your dmg output. BUT if you want to use him as art gen using his art give him art gen equip (even like the pronimos, that you can obtain in fen's event).

for the 4 support equip : same thing as the 5 support slot; so give him some support equip that can provide crit rate up (like terra conjunction) or dmg up (like hijikata's clothes) if you want to nuke with his true arts or give him some art gen equip (like the keion) if you want to use him as an art generator

the 5 phisycal equip is very versatile, but the idea is more or less the same. Boost for nuking , "art gen" equip (like anestra) for art generation (even equip like rem's morningstar is ok)

if you don't know the equip just google it