Are you possibly confused looking for a 32k x 8 SRAM that is described as a 128k part instead of described as a 256k part, where the confusion possibly comes from the manual saying there is 128KB of cache (made up of four 32KB parts).
If you have been looking for 32k x 8 SRAM parts that are described as the usual 256k parts they shouldn't be hard to find. One example is the Cypress CY7C199CN 15ns 32K x 8 SRAM part which might work for you.
You can currently buy CY7C199CN-15PXC parts brand new from Mouser for $2 each, or $1.82 each if you buy 10.
Probably haha. I literally just got it yesterday. Spent a couple hours cleaning it and then the better half of the evening setting up DOS. Like I said I am really new to this.......The last time I saw a pure C:\> was when I was 12 and had a very limited knowledge of the hardware and software of the era.