Not an expert here but could assist with some concerns you have raised.
1) I personally think the skimmer for the iq5 is not necessary and you could focus more time on regular water change as a form of nutrient export. However since u already bought it, I understand that it is a airstone skimmer so I guess u would require some form of air input... Doing an online search should yield you some decent results.
2) you might want to consider including a fan/chiller to keep temperature done... We reside in a ridiculously hot country. Maybe something to increase water movement within the tank?
3) you could get your hands on a refractor meter think most LFS carry them.. Accurate, convenient
4) many around. Check out some of the sponsors here
5) media wise you could use some biohome, ultralith, mechanical filter like sponge (do remember to change regularly) activated carbon and some form of nitrate/phosphate export... Fish only may not be necessary
Have fun bro!