"Pinks" here means "bills," but it isn't very common slang. "Visa" is their credit card bill. "Cable" is their television bill. "Let float" means to not pay for a month (and catch up the next month and pay for two months when there is hopefully more money.) So, yes, you're right. They owe too much money and have only enough to pay for one bill. They're trying to decide which to pay and which to ignore.

Just checked that episode of "Malcolm in the Middle" - it was just a color of their bills. The wife was holding two pink bills in her hands, when she asked her husband that question.

Hi I think it's kind of a ship or boat or sail, since we have the word float here. and also I think cable means anchor.