Look around for a basin that is long but not super deep. If you have the room, a decorations Rubbermaid bin might be good. My friend made a darkroom sink out of a shower pan and it’s actually pretty fantastic.

As for the color chemistry: I would highly recommend sticking with the simple kits. C41 processing can be very particular, which is why it was done with dedicated machines. It’s easy to overshoot a bath when you have to fill and drain a tank. The kits take this error out of the process. Plan on ruining some rolls before you get it right. Don’t expect perfect color balance and tones and have fun experimenting!