Totally get you! I was the same way when I started my first tank and I wanted to get everything exactly perfect. Did hours upon hours of research and devised a serious game plan including a go at the DSM too! Funnily enough, many things didn't go according to plan but it all came together in the end, because in my experience, many aspects of this process are quite forgiving which is definitely a relief.
Just wanted to add a few things:
1. You might not need to go as high as 4-5ppm ammonia depending on how large your tank is/how heavily you will stock. I also read through various sites on the cycling process when I was attempting mine and most said 4-5ppm as a standard but I've learned that it is not really necessary when your tank is on the smaller side. I started off trying to cycle with 4ppm ammonia, but the cycle wouldn't budge and so I came to TPT for help and I learned from another user that for my 10g tank, I really only needed to cycle with about 1-2ppm ammonia. Most cases, in a smaller tank, 4-5ppm is more than the livestock would ever really produce in a single day. And so for a tank that's 20g, you could probably get away with 3-4ppm instead of 4-5ppm. I think I stuck to around 1.5ppm for my cycle and once I stocked my tank, everything was perfectly fine, no problems in my cycle at all ever since.
2. If you do decide to stick to the higher range of ammonia, I might caution from putting plants right away as some plants could melt from ammonia burn when the ammonia is too high. Depends on the plant, and of course how much ammonia there is, but if you start out high, you might want to wait until the ammonia lessens a bit just to be safe.
3. If you use a bacteria starter, it's very helpful to pour some of the liquid straight onto your filtration media so some of the bacteria have a head start in establishing in the media. As for me, I shook the bottle vigorously before pouring half the bottle in the water column and half straight into my filter where my filtration media was. Not sure if it made a difference, but it cant hurt
By the way, the user above recommends Dr. Tim's bacteria starter and I heard so many good things about this product. It's said to be one of the few bacteria starters that have the true, live nitrifying bacteria that is needed in the cycle, which is why I definitely considered using this product before I tried tetra safe start. A lot of articles said other bacteria starters dont have the right bacteria in them and don't do much for the cycle, but I found this to be false. I definitely would have tried Dr. Tim's bacteria starter if it wasn't so hard to get ahold of, plus it's a bit more expensive than tetra safe start. Tetra safe start is carried at most chain pet stores and is on amazon for pretty cheap. I took a chance and it turned out to be worth it in this instance so I would definitely recommend it. I also tried API quickstart, but that didn't do anything for me.
Hope that helps. Wish you lots of luck on your tank!