Im sure this has already been answered elsewhere but i figured a direct answer to my question would be easier then piecing together answers from different threads.. so here goes..
I play lux as my main champion, whether its solo mid or supporting a bruiser.. my question is about stacking items to work with her passive..

Illumination - Lux's damaging spells charge the target with energy for 6 seconds. Lux's next attack ignites the energy, dealing bonus magic damage (depending on Lux's level) to the target.

If i were to stack illumination with lichbanes passive
( UNIQUE Passive - Spellblade: After using an ability, the next basic attack deals 50 (+75% of Ability Power) bonus magic damage on hit (2 second cooldown)

AND

Malady's passive : UNIQUE Passive: Basic attacks deal 15 (+10% of Ability Power) bonus magic damage on hit.

Could all these passive proc on 1 hit? i know unique passives with the same name dont stack but they have different names.. lol sorry if this is a stupid question.. was just wondering.. Trinity wuold be another item stack option but the AD is kinda pointless..

Yes, they would all proc on the first hit. A good thing to keep in mind is that Spellblade has a 2 second CD. so to get the most use out of it time out your abilities accordingly.

If youre going full AP youll probably benefit more from a combo burst. Example: Hitting an opponent with Q, E, R in rapid succession. Lux is squishy so its pretty risky to hit them with your q, then get in range for an auto attack because any half decent assassin can take Lux out once the stun wears off if shes still in range.

Lichbane is a recommended item in Dominion however because youll often be in teamfights where youll have to stick around for a while instead of hitting the opponent and then backing up to the safety of your turret.

Hope this was helpful advice and goodluck!