Right now, probably the lowest cost, purpose built platform for this is probably the Ridley Noah Fast 3.0. I felt like there was a rumor of a Seka but it hasn’t shown up yet. Maybe Tavelos 2nd gen Arow will closer?
In terms of what you might have: The Velobuild 368 might be an OK platform to experiment. The other one would be the Quick Pro Er:One if it’s an XL and you are willing to give it a try.
Rather than start with short cranks. I would keep your 170s for now. If it’s the Quick Pro you probably would want the zero offset post if you dont have it.
If it were me, I would do the activity described below:
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Set the bike up on the trainer and set up two video feeds, one in front and one to the side. Measure your saddle to bar distance.
Then just move the saddle forward in “coarse” adjustments of 10mm to see if you can get rid of the knee movement. If that works, then move the saddle up like 20-25mm, enough to make the pedal stroke a little choppy. Slowly in 5mm increments move it down. Note where it comes smooth again. Continues to slowly move it down until the knee movement returns. Then back up 5mm. Note the position. Move the saddle forward 10mm and repeat until you run out of rail of it just feels strange continuing to move it forward.
You should now have a range of saddle positions that work for you. If nothing works then you definitely should try shorter cranks.
Try out a range of these positions in and out of the saddle, sprinting / sitting back down, climbing etc. Find the one that feels the most natural and see if you can get the same saddle to bar distance with an available stem and bar. IF you cant then, try a combo that works.
As i get older and because of injuries from when I was young, I increasingly find that the lower positions are better as long as they dont cause other issues.