PS/1 INVESTOR type # 2155-P85 Hard Drive

Hi, I am totally new here, and have joined as I now have two PS/1 machines; a Consultant and a Investor 2155-P85 50 Meg job minus it's hard drive. And with a third machine another Investor (supposedly scrap ) as a potential source of spares still on it's way from the US.

I have spent the last fortnight "harvesting" every scrap of PS/1 gen I can find on the Web.

Based on that I have managed to clear the password and bring up DOS 5 from floppies on the Consultant. I am very impressed with the quality of the hardware engineering on both machines, unlike "modern" tin-box PC enclosures.

So why I am here. I am looking for source for a IBM OEM DSAA 3360 386 MB hard drive and information if it is an IBM special interface or bog standard ATA interface so I can stick one of my old drives in.

And also pointers to a source for decent software tools such as dissembler, assembler, K&R C compiler, [forget about either ANSI or C++, I talk K&R C] linker loader, library manager etc. That will run on i386/i486
Unfortunately I had all that stuff right from back in CP/M days (yes C on a Northstar CP/M machine) and got rid of them once I had access to a Green Hills C Compiler on both VAXs and large multiprocessor UNIX machines for work. Now I am starting again (as a hobby) so any pointers will be very appreciated.
many thanks and best regards, OldBlueBear