I have the original LGO cables too - cutting and crimping would be an option. But I found that the crimping tool is expensive and crimping that lot of cables is "not an exciting job" - and I have to buy all the LEGO cable and throw away one connector.
Woud be ok for 1 or 4 cables but not for 200pcs up.
(I have to take care, that the costs for our clients should be very low - we are private people without sponsoring.)
I looked at the JPL mars rover and think it should be easy to make.
I will redesign the main mechanical parts, so that I can use 3D-printed parts, for the weel-drive-motors I'll design my standart motors. (wthout decoder) and for steering I'll design medium servos. This combination works perfect for vehicles in that size. In this design 2 DC motor drivers and 4 servos will work. So I can use the GoPlus2 module.
The plastic parts have a simple design, so I can use them for my training.
As far as I guess a M5Stack in the "face display" would be easy to include and the display would look good.
So the complete control unit will be the M5Stack Core2 and the GoPlus2 - very compact.
I'll make one side of the rocker bogie suspension and will simulate it.
For that quantity you should invest in the tool!
I used to use a pair of needle nose pliers to crimp 2.54mm pins and i broke loads (still break them even with the tool)
The connectors are on ebay and LCSC
I've tried asking for the firmware for the go unit but they say it not reprogrammable.