Next upgrade: cables. But which ones first?

Please help with guidance regarding cable upgrade. I’m a total cable novice. So far I’ve focused on upgrading components and I think the next move should be cables. But where to start?

I have B&W 804S speakers, McIntosh MC275 amp, Lamm LL2D pre, Rotel RCD1072 cd player, a Squeezebox Touch, and I plan on getting a DAC in about a year. I have two 10 AWG dedicated power lines with hospital grade outlets, and the system makes no hiss, no hum. All power cords are stock (none shielded), speaker cables are magnet wire (DIY anti cables), and ICs are Nordost cheapest RCAs.

I’m trying to decide whether to upgrade speaker cables first, or power cords first. While ICs are still cheap, I guess they are a small step above the speaker and power cords. I also realize this is yet another form of source first vs. speakers first debate. Yet I need to decide what would make a larger sonic impact for about $1000. I could buy used in the US or DIY, but I’m overseas so getting a bunch of cables and trying is not an option.

Thank you!