Hey, welcome to the site. Heres a few things off the top of my head!
Catalina lights are super affordable and can be made custom fit to any size aquarium. Watts per gallon is a very old school method of measuring how much light is needed, and shouldnt even really be considered. More importantly, you should think about how much PAR you would receive at the lowest part of your tank (ie, the substrate). These levels are measured in high, medium and low intensity. Then, its quite easy to look up certain plants you are interested in and see if its appropriate to get that for your tank, depending on how much light you want. Heres a good thread to read up on:
However, you can't simply say you want high light and high light plants. To go high light, means you need ample amounts of co2 and ferts, or else you will run into serious algae and deficiency issues.
Another lighting option is LED's. They are vastly more efficient than t5's, but also not as affordable. If you are simply looking for an affordable entry level light, t5HO's are your best bet.
One of the better, cheaper canister filters is the (SunSun, Aquatop, etc) CF series. I currently set up an AquaTop CF300 and love it. It works great, and is really affordable. You may want to look into their other versions for your 45g.
As for full hoods, I think the simplest solution is a glass top with a fixture that stands, or hangs. That way, the light can be varied by height if you run into issues with algae.
Finally, a suggestion. Tetras are schooling fish, and having 1 lone black/white skirt by his/her self is probably extremely stressful for it. I would for sure get at a bare minimum 5 skirted tetras.
PS. I know nothing about newts
Late Night Edit: DIY CO2. Usually suggested for smaller aquariums, but of course its possible to use multiple 2L bottles to achieve good results. However, DIY CO2 is simply not as reliable as a pressurized system. I have DIY on my 25g, and the levels are shaky at best. For optimal growth, and health of your fish, stables levels are important. That doesnt mean you shouldnt try, though!