I used Nova's GRE Math Bible for GRE preparation and it is an awesome book. Infact it is "the most" recommended book for GRE Maths. The content of GRE Math Bible is similar to that of GMAT Bible except for the Data sufficiency section.
Geometry section is covered very well in this book.
However if you need to get just one material for for GMAT Maths,I think the MGMAT books
are a better option.