I made my 1400 from two mostly complete units. This gave me the maximum RAM (IIRC 64MB),a G3 processor, and active TFT screen, as well as various extra accessories. Only other things I bought were a 20GB hard drive and a Focus ethernet adaptor. And all of my batteries were dead, just like most of them out there are. I have thought about re-celling mine, but pause and think about redoing them for lithium-ion cells and charger.
Note that a weird limitation of the 1400 is that it can have only one LAN driver installed. With my Focus RJ45 port, I had to completely uninstall the driver in order to use an 802.11 card. It's too much trouble so I just use regular ethernet.
Also, if you go the G3 route, be sure to get a newer version. My old NewerTech one runs so hot that it has melted part of the casing. The newer 400 MHz upgrades like those from Sonnet supposedly run much cooler. Also a G3 won't run alternate OSs such as BeOS or MkLinux but those aren't supported on a 1400 anyway. I found that MacOS 8.6 is happy on mine, 9 uses too much of the scarce RAM. If you have less than 64MB of RAM I suggest an even older OS.