ROM 00/01 to 03 upgrade on an IIe upgraded to a IIgs?

["Jayson Smith" <ihatespamratguynospamplease@insightbb.spamsucks.com>]

Hi,

I've recently been in contact with someone who has an IIe upgraded to an 
IIgs. He has 256K of RAM, so that almost certainly means he doesn't have a 
ROM 03. Both of us are blind. I've never seen an IIe upgraded to an IIgs so 
don't know how those work. Does it use a completely standard IIgs 
motherboard? In other words, if we were to find an IIgs ROM 03 motherboard, 
could he do a motherboard transplant?

On a slightly different topic, is there any source other than eBay and other 
secondhand places for memory expansion boards for the IIgs?
Thanks.