Often you can find breakers selling pedals with the plug.

I think Tim at https://jti.uk.com/ can supply connectors though.

And pedals or DBW units do not need to be linear, you'd be calibrating them all yourself anyway but it is a little easier if they are linear. But most units are all different. Some have 1 up, 1 down, some have both going up, some have one linear, the other not.

Really doesnt matter at the end of the day. I've heard some where the sensor does not actually cover the full motion of the blade though...those are definitely to be avoided. Seems bizarre any manufacturer would even do it, but apparently some Toyotas do.

But again, the most important aspect with DBW...is what your chosen ecu will be happy with.