All of those are too little for too much...
My eventual plan was to use a 133MHz 486SX computer with a cost of under $100. Put linux on compact flash and have it boot into a terminal program. Much more versitle. It even runs X windows so you can look at PDF manuals on one of the outher consoles.
http://www.compactpc.com.tw/
I've personally used the eBox mini and it works great. I ran Debian linux on it. The standard distribution installed on it. The FPU emulation was in the standard install kernel.
I'll try to get to the other messages on here.