Fortunately, the Metrowerks folks provided an interface by which one can replace SIOUX with another package. I've put together a SIOUX replacement which uses the Communications Toolbox's terminal emulation to create a VTxxx-compatible console package. The terminal-window code itself is based heavily on sample code by Craig Hotchkiss. The package is still rather rough, but since some people have asked for it, I present it here. I hope you find it useful, and I welcome any suggestions you have for making it more so.
TermWinScrolls: If this short variable is set to 1 (or any nonzero value), the terminal will have scroll bars. Scroll bars now work without crashing your computer (whew!). However, the size of the virtual document is not large; you probably won't use the scroll bars unless you shrink the window.
gConsoleQuickInput: If this is set to a nonzero value, then input routines which request a single character may receive it as soon as a key is pressed, instead of waiting for the user to press Return. This is a very useful feature, but the default behavior is the old terminal standard. Set it as you wish.
gConsoleSleep: This global variable determines how much time the console window gives other processes while waiting for an event. The default value is 5, which means that it will yield to other processes for 5/60ths of a second before demanding attention again.