My understanding is the same for USB screen limitations.
You may want to consider a full sized monitor (typically DVI input) that has the touchscreen capabilities (typically a USB output). Be aware that there are several different touch screen technologies employed (ie. Resistive, Infrared, etc.). Most likely, mounting TM MFD bezels in front of the touchscreen will pose a minor challenge (you need to avoid having the MFD Bezel touch the screen). If you have an infrared based touchscreen, such as the Acer T230H, then you probably need to allow a bit of extra clearance, as you don't actually have to touch the screen to be detected as a touch (just get really close). Mounting the TM MFD bezels in front of the monitor can be done though, if you really want it.
Fortunately, you don't have to use the TM MFDs that way, if you are open to another option. Take a look at the Helios software, as it can put touchscreen MFD button rings on the screen. You would lose the spiffy physical buttons that you have now, but would gain a lot of flexibility (ie. place the MFDs in different screen positions for different sims.). You could still use the TM MFDs as inputs (perhaps for things that are fairly universal to multiple sims). TouchBuddy was a great contribution to the sim community, but the last I read, it wasn't getting actively developed any further. It's probably best to look at what is actively getting developer attention, in the interest of longevity.