Hi,
I've always used -- and still using -- SAS/C (currently version 6.58).
Back the days I've used AmigaOS 3.1 and only had have 5 MB (1MB chip- and 4 MB fastram) in my A3000T (68030/25MHz that days), I've had no problems in building any project, there was so much memory free during compiling, I've thought about speeding up compilation by copying the compiler and all include-files into ram-disk.
I know that you can install SAS/C on floppy disks and so, I think, SAS/C will run on your machine (and I think it is still the best C-compiler available for Amiga, even if C++ is compiled by translating it to C by a preprocessor). The greater problem will be to get it. You should have a look at eBay.
Noster