Yeah the LT is totally portable. Especially with the CD unit and an external controller attached to it.
Adding PCE console specific layer on top of that, makes for an interesting challenge (no, not a reference to Ys II).
It doesn't have to be connected to the CD unit or use an external controller port, however it still isn't necessarily "portable" because you need to use an AC adapter for it. However there is some rare battery pack designed for it.
If you get yourself some 2500mah+ nimh batteries, you can get some decent battery life out of the GT or Express. I usually get about 2.5 hours or more.
Will be a blast.
Us Turbo fans are like cokeheads; we may be poor, but we spend all the money we can get on Turbo stuff.