https://www.amazon.com/Zoo-Med-Reptisun-T5-Ho-Fluorescent/dp/B00AQU8GF0 and this for heat https://www.petsmart.com/reptile/environmental-control-and-lighting/bulbs-and-lamps/zoo-med-repti-tuff-splashproof-halogen-lamp-5120585.html?gclsrc=aw.ds&gclid=Cj0KCQiAm5ycBhCXARIsAPldzoVuZPXWSMbSt3PMNnY3cNK-k88cRq5pQ5-LQKbM125dc6X4vYulGXEaAsUrEALw_wcB

Check out reptile mountain on youtube. He has some really good, in-depth videos on topics like substrates, humidity, enclosures, uvb and diet. The light you need is going to depend greatly on your setup. For UVB, I use a reptisun 5.0 t5ho. The Indonesian species fall into 1-2 Ferguson zone, closer to zone 1. Their UVI should be at or below 1.0. I have my skink in a 4x2x2 enclosure and that light works perfectly for my setup.

You said you were looking at a halmaheran. Just a heads up, it will almost certainly be wild caught. There are very few successful breeders of Indos. If you are unaware, wild caught animals have a much higher risk of things like parasites and sometimes just plain don't do well in captivity.

The Indonesian species also tend to be much more shy than the Australians. My halmaheran was so shy I named her Cloverfield because I only ever saw her tail disappearing into a hide for the first 6 months I had her. They also need ~80% humidity.