Uploading System 6 via a PC?

[(Richard Nurse)]

I've just become the proud owner of a IIGS (they're pretty hard to come by
here in the UK), but unfortunately it only came with a Prodos 8 boot disk
(also containing UnShrinkit 2.0) , and a disk containing Proterm 2.1 
Naturally, I'd like to get System 5 or 6, but what are my best options?
Unfortunately, I don't have a Mac (though I can get occasional access to
one), but I can XModem stuff between my PC and the IIGS. Is there a binscii
decoder for the PC ( I've got Nulib, so I can unshrink .SHK files). I
realise that I could send the binscii files to the IIGS and then un-binscii
+ unshrink them there, but I wouldn't have enough disk space for both the
binscii'd file and the extracted files (I've only one 800k drive and not
enough memory for a large RAM disk). 
I can use ADT to copy disk images from the PC via cable to the Apple's
5.25" drive - is there anything similar that copies prodos images from the
PC to 800k 3.5" disks?
What are S16 file types - presumably System 5 / 6 system files? (they don't
seem to run under prodos).

Finally, on the subject of memory, my RAM card contains 512K (just the top
half filled). What are my options for expansion?  I assume that filling the
bottom half with 41256's will make 1 Meg? If so, what should the J1/J2
jumpers be set to? Does the RAM all need to be the same speed (the top half
is 150ns).


					Cheers,


						Richard.