/ only seems to get about 14Mb and if it had more it wouldn't get filled up by conf files and operating overhead. I think is question is simply, how do we get more? A different rom image?
No, it doesn't work that way. Let me try to explain:
A Z5500 has exactly 16Mb of flash. It's a dedicted chip on the mainboard of your Z.
And since the flash is mounted as / on your Z, the size of / can not be bigger than
16Mb. Ever.
In addidtion to the 16Mb flash, the Z5500 ships with 64Mb of RAM. Some of this RAM may be
(ab)used as storeage area for your files (/mnt/ram). If you choose a kernel with a 32/32 split,
32Mb of RAM will be avalable as /mnt/ram, and 32Mb will be used as RAM to run programs.
The problem with /mnt/ram is that everything in it will be lost after a reset.
A stock OZ 3.5.2 Opie ROM (dunno for GPE) leaves you with ~2Mb of free space in /.
That's more than enough for symlinks and config files.
Just install
all programs to your SD card and you will be fine.