There is no advantage to DDR4 right now. None. The clock speeds are faster, but the latency is generally about double that of DDR3 because of the lower voltage, so you're giving all the performance increase right back. In most instances, DDR4 is actually SLOWER than high-performance or even mid-high DDR3.
To get a rough idea of the "true" RAM speed, divide clock speed by latency, so:
Your set of DDR4-2400: 2400/15 = 160
7 latency DDR3-1600: 228.57
The ONLY reason you would have any gain from "future-proofing" with DDR4 is if you plan to reuse it in your next system ... but since a new Intel CPU/motherboard combo should be good for gaming for 6-7 years with a GPU refresh in the middle - are you really going to reuse that same set of RAM for a new system you build in 2022, when DDR5 will probably be all the rage? No, I didn't think so. CPU, motherboard, and RAM are all one-and-done right now.
Anyway - that aside, the obvious way to save a few bucks would be to lose the fan controller, and depending on how much storage you REALLY need, either make the 1TB black your main drive and skip the SSD until later, or go with a 256 GB SSD as your main and add a storage drive later.
In either situation, I would not go with a 120 GB solid state drive as your main - you will get tired of the low capacity REAL fast. Much better to go with at least 256 if using a HDD for mass storage; if you can afford it, a 500+ SSD is extra convenient because it lets you just keep everything in one place. Either one would be a valid reason to skip the 120 for now until you can get one with better capacity.