Although I have no experience with Fat Man, they advertise that they have made IFS for many different chassis. With luck, they may already have a design that will fit yours.

The Carroll Smith book the Tech suggests is a very good primer and will give you a lot of good suggestions on what makes a chassis/suspension work. What it is NOT is a recipe on how to build one that will fit yours like a glove. The book that precedes it 'Prepare to Win' should be included as well. Then there is a third, 'Engineer to Win' to finish the series and I do need this one to finish my collection (Richard, you are costing me $$$$)