I would like to daisychain a monitor through an external hard drive, using Thunderbolt. Are there any hard drives with an additional Thunderbolt port? Preferably compact and affordable. I would also be interested in an external HDD/SSD enclosure with the extra daisy-chaining port.
The drives with two thunderbolt ports are intended to work in a chain as opposed to the drives that only have one port. By necessity, these can only exist at the end of the chain.
Armed with this knowledge, you can always look at whatever models are for sale when you are considering a purchase and decide whether the added cost to have two ports outweighs the need to have a chainable device or buy a hub should one be eventually produced as a stand alone device.
The LaCie Little Big Disk supports daisychaining and includes an extra port for it LaCie Little Big Disk. At $400, it's pretty comparable to other TB disk drives I've seen on the market.