Switches for a midi controller

[hospadar]

I'm wondering if anyone knows any switches which could be used in midi controllers which would give me the ability to detect note velocity.

Are there any standard solutions for this, any switches or pushbuttons which can be purchased immediately

I imagine this could be accomplished a couple ways:
1) A "switch" which is really just a plunger that trips 2 photodetectors, one at the top of the throw, one at the bottom. This sounds a little painful to implement to me, but if I could find the hardware, driving it and detecting it (with a microcontroller lets say) would be easy

2) A pushbutton switch that has 2 sets of contacts, one which is perhaps NC, the other which is NO. when pressed, the NC contact would open immediately, and the NO contact would close at the bottom of the throw

3) some kind of springy plunger-type potentiometer. I've never seen anything like this, but I can't imagine it would be to hard to build.

4) some manner of teeter-totter (like a piano key) placed over 2 buttons, with a spring so at rest it closes one button (let's say with the back end), when pressed (at the front end) it closes the front button after opening the back.

In all situations I would use the time between the button leaving the home position and reaching the end of the throw to compute velocity so I can have my midi controller properly emit note volume

EDIT:
I should mention, I want to use these in a very simple (probably just one octave) midi controller. I just want to want to play around with building a simple controller before I attempt anything more ambitious.

I've attached a little gif to help illustrate where I'm going with this

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