op - yes you should keep the lengths the same
seems like you have plenty of ’advice’ here, maybe more than you need
i would reiterate the comments of those that say get a decent tonally balanced cable of sufficient gauge to allow for bass control from the amp, prioritize getting your setup dialed in optimally (e,g, room, placement, isolation and so on) before you go hog wild spending on cables, it is low return on investment until you have other higher priority bases covered

