1) Filtration (eg. canister?) - canister type not recommended as most are just nitrate builders
2) Skimmer (eg. hangon type?) - have good reviews of mce600 (most commonly sold 2nd hand hangon skimmer)
3) Lightset (eg. T5?) - t5 proven track record, can go for de-lightings or ati
4) Chiller - artica is like the best but most ex, resun cl650 is the most common 2nd hand product that most people are using.
5) any other equipment needed. - there are tonsss, depends on how u gonna want to maintain ur tank in the end (DI unit is the 1st step i believe)