Just so you know what you're getting, just go to your local Best Buy and pick one up in person.
I would go with the Motorola 6141 as that is 8x4 channel bonding. I personally have no experience with Zoom modems so I cannot speak for their quality but I've had good luck with Arris and Motorola. I prefer to buy Motorola when I buy an HSI modem and Arris for CDV modems.
Just whatever modem you buy make sure it is DOCSIS 3.0 and 8x4 channel bonding capable.