I have before implemented a complete (2 address instruction set architecture) micro-processor simulator, along with it's assembler using Java. Although the implemented micro-processor was a different architecture than MIPS, but both architectures are very similar. I have very good experience with Java, and consequently, I will be implementing your simulator using Java. The project should not take more than a day, and if there are further small refinements you would like to add, I'd be happy to add them free of charge. Looking forward to hearing from you.