Hydraulic Disc Brake (how to choose correct model)

I recently broke off the lever of my front brake and am looking for a replacement lever or front brake. Need some input/suggestions from more experiences riders.

Some of my questions:

• What are the (dis)advantages of multiple pistons (for example a 4 piston caliper) better than less pistons?
• Would cooling fins be recommended? (I don’t ride downhill but do brake hard and often)
• Is there a way to find the piston size/lever ‘leverage ratio’ without having to ask each manufacturer?

I originally had a Magura MT4 which I was very happy with but I fell and the lever (more specifically the fluid reservoir) broke in half (due to it being made of plastic). If I could get something similar in terms of braking power which is a bit more robust (not made of plastic) that would be great. Alternatively I could install something similar to this to prevent the lever from breaking/snapping (I believe they’re called “lever guards”):

The bike is very heavy (e-bike), approx 45kg and fast (70kph) so I need very good braking power. With the MT4’s I could do a stoppie (riding on front wheel only) with 2 fingers on the lever.

I replaced the broken off lever on my MT4 with a Shimano lever (not exactly sure which one, will add photo below) but for some reason I have to press the lever way way harder (on MT4 I needed 1-2 fingers with very little force to block front wheel (dry tarmac) and with the Shimano lever I need to press as hard as I can with 3-4 fingers and still can barely block the front wheel) to get the same stopping power (same caliper/hose, different brake lever).

Shimano lever:

I have tried looking for replacements online but could not find the ‘leverage ratio’ (leverage of the brake lever itself and the size of the piston in the brake handle) anywhere in the spec sheets for the models I’ve looked at. I am using a 180mm Magura brake rotor.

I think a downhill type brake would be the best option.

Brake Requirements:

• a lot of braking power (block front brake with 1-2 fingers without much force)
• Weight is no issue (they can be heavy)
• price under 120usd/100eu if possible (if there is a big difference in quality/performance when going a bit higher budget please don’t refrain from suggesting a bit more expensive models as well)
• adjustable bite point/reach for bonus points
• they do NOT need to be e-bike specific (no brake sensor needed)

Any suggestions are welcome/greatly appreciated. Thank you!

Original (broken) MT4 lever: