What ram should i get

What is the budget for your system?
What do you need included?

What's your monitor situation?
Do you need one included?

Will this be a gaming PC only? Streaming? Video editing?

There are several factors you should consider in selecting the RAM:

1. DDR Slot Format / Build Platform
Assuming you have a fairly new PC build, the DDR format can either be DDR3 (fairly older platform) or DDR4 (recent platforms). A DDR3 has a different pinout (and voltage) than a DDR4. One won't physically with to the slot of the other. So, check what DDR and platform you have.

2. Capacity and Purpose
RAM capacity (in GB) is the most noticeable difference in RAM performance. A total of 4GB RAM capacity is too low nowadays. 8GB is widely-considered as "bare" minimum. 16GB is ideal, especially for multitasking/workstation use. 32GB is too much for casual use unless you are into professional editing work.

3. Number of Slots in Motherboard
The quantity of RAM sticks also plays into consideration, which is dependent on the number of slots your motherboard has. Buying a pair of RAM modules is ideal (taking advantage of Dual Channel) as it has been tested out-of-the-box to work as a pair, instead of buying a single stick and later on adding another. If your platform supports Quad Channel, then consider getting a set of 4 RAM modules.

4. Max. Supported Speed
Speed (in MHz) is the determinant (after Capacity, in GB) in terms of selecting a faster ram (instead of CAS Latency). The governing factor in selecting the RAM speed is what your CPU and Motherboard can supports at maximum. In DDR3, for example, non-OC CPU/motherboards only support up to 1600MHz. OC'able CPU/MB can support from 1866MHz and up. In DDR4, default sppeds are 2133MHz to 2400MHz for non-OC platforms, while 2666MHz and up can be used for OC'able setups.

5. RAM Height
The actual, physical height of the RAM modules play into consideration especially when using large CPU (air) coolers as there might be spatial issues in mounting such coolers that may block or hinder the installation of the RAMs.

6. Color and LED
For purely aesthetics only, if you want to match the RAM module's colors (and LED lighting bling-bling) with the rest of your build.

In real world use, the RAM capacity (in GB) is very noticeable compared to the RAM speeds (in MHz). So, focus on what specific use your PC would be and select the affordable RAM you can get with the ample amount of GB (and number of sticks). The speed should be secondary in priority (esp. if you're not going to OC).

Get this.
Swap the case out for an S340 Black imo as it is currently about 50 bucks on sale, stick with the Air 540 if you want.
PCPartPicker part list / Price breakdown by merchant

CPU: Intel - Core i7-7700K 4.2GHz Quad-Core Processor ($329.89 @ OutletPC)
CPU Cooler: CRYORIG - H5 Universal 65.0 CFM CPU Cooler ($46.88 @ OutletPC)
Motherboard: Asus - STRIX Z270H ATX LGA1151 Motherboard ($147.99 @ SuperBiiz)
Memory: G.Skill - Ripjaws V Series 16GB (2 x 8GB) DDR4-3200 Memory ($109.99 @ Newegg)
Storage: Samsung - 960 EVO 250GB M.2-2280 Solid State Drive ($127.99 @ B&H)
Storage: Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($65.69 @ OutletPC)
Video Card: Gigabyte - GeForce GTX 1080 Ti 11GB Gaming OC 11G Video Card ($683.99 @ SuperBiiz)
Case: Corsair - Air 540 ATX Mid Tower Case ($114.99 @ Jet)
Optical Drive: Asus - DRW-24B1ST/BLK/B/AS DVD/CD Writer ($18.69 @ OutletPC)
Total: $1646.10
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-05-21 21:20 EDT-0400

Just be aware if you get the 340 you can't top mount the H100i. That could be why the Cryorig is in there. I prefer the Cryorig over the H100i.

Yes, it'll handle any OC you throw at it and keep the CPU cool, performs nearly on par with the Noctua NH-D15, one of the best coolers on the market, and at half the price with a lower weight.

I too value silence and performance over bling, that's why I have a kraken x61. The h100i series are good, only if you swap out the miserable chunks of plastic they call fans, at which point you could have easily afforded the better kraken.
Did notice 1 thing though, not a single build includes a psu.