The first method is probably the best method to start with. It will familiarize you with supplement addition to a lightly stocked reef aquarium with a few LPS and SPS corals and wont cost you a small fortune to maintain good water parameters. After some time with growth and increased stocking you will notice the increased consumption of these important supplements with increasing cost.
The use of a calcium reactor and kalk stirrer is a very effective way of maintaining calcium and alkalinity. The problem with this method is the outlay of the equipment,and unless you have a large aquarium (500 litre plus) highly stocked with LPS and SPS corals demanding high consumption of supplements.I just think the outlay is not justified.
Balling lite is becoming the most popular method of supplement addition for small and medium sized reef aquarium. Simply using balling salts of chemicals used to increase/stabilize each supplements. After working out the daily consumption of each supplement. You simply dose that amount daily, either with the use of dosing pumps or manual dosing from a syringe. Balling salts are mixed with Reverse Osmosis water to correct ratios and then is stored in water tight containers and used as required. Really simple and inexpensive start up costs.
To conclude, if you are new to reef keeping. Learn and get used to manually maintaining parameters by using off the shelf additives, then as you progress and start stocking many SPS and LPS corals move on to the "balling lite" method. If you then decide to keep a large reef aquarium of 500 litres or more, you might consider the use of a reactor and stirrer.