Switches are what mainly determines the sound signiture of each key stroke and there are two types:

Tactile vs linear.

Tactile switches allow you to feel a bump indicating activation of the key whereas linear switches have no bump. There are a variety of different versions of both types of switches so it is recommended to trying out a few before committing to a whole bundle. In addition to their stock sound, you can add lube to significantly decrease the amount of scratchiness and smoothen the sound.Because this is a basic guide, I will not go deep into modding so here is a tutorial if you are interested.

Now that you have gathered your switches, it's time to discuss stabilizers. Stabilizers are required for keys that need to balance out a key press from any direction such as the spacebar, shift key, delete key, and enter key. For a 65% keyboard, we will using three 2u stabilizers and one 6.25u stabilizer. Stabilizers also affect the sound of a keyboard so be sure to be comfortable with whatever you choose. It is ideal to listen to sound comparisons online, but do remember that they may not reflect how yours might sound due a variety of reasons.