hi bro, welcome to this exciting hobby
as I had tried to convert sumpless freshwater tank to marine before (tank crashed eventually), like to share my 2 cents worth:
1) no sump - you will need canister filter - can be very tedious / messy to service when you have salt water. & may become a pain to do weekly maintenance after the initial excitement died down
2) hang on skimmers - can be a challenge if you have bracing on your current fish tank
3) Aquazonic T5 was good enough for many LPS, no problem when I was keeping my prata, cynarina & torch Needs stronger lighting for more challenging corals
4) I am using the jebao Wp 25 now - so far so good, comes in different programmes too
5) Other eqpt - depending what you want to keep, may have to consider getting FRs as no refugium, but need to consider where to place these
6) test kits - if you are planning to keep LPS / SPS in future - bought many Salifert test kits (NO2/ NO3/ Calcium / Magneisum / KH / PO4)
not to be discouraging, with so many equipment hanging around, it may disturb the beauty of a marine tank that we want to achieve. then will spend another big amount to upgrade - that's what happened to me.
do think of the other option of getting a tank with sump. To keep in the 1.5k budget, you can look at the pasar malam section where reefers are selling their tanks / equipment.