Compact motor for Supra

Hi everyone ! Please tell me if I should ask somewhere else if it doesn’t fit this sub ! So, I’m currently trying to improve/modify the FF Supra in order to have it motorised and 4WD Managed to do all the differential, turning system etc… but now I don’t currently own a Lego motor and they look huge with the battery box… So my question is simply : is there any good option at a reasonable price (around lego price let’s say) that would fit in the limited space available, while including the...