Reference books

I am not well aware about foundation syllabus so can't recommend a particular book, but the list of recommended books by Institute is itself available in modules and prospectus also.  You can take an idea from it.

Also at inter/final level for theory subjects module of institute is usually sufficent, hence for foundation also i think first preference should be given to module & for practicals I think +2/B.com books will help u as per your syllabus.

For Company Law you must use G.K. Kapoor, there is no any other option for this subject.

For Taxation Taxmann's Singhania is Best.

And for other subject your CS module is best