Hi Sandra
Unfortunately even with SAP GUI 730, there is only a 32-bit version available. No news as yet on whether the successor to SAP GUI 730 (expected next year 2015) will include a 64-bit version.
With regards to SAP BW Business Explorer, an alternative to consider when using Office 2010/2013 64-bit, is you can use the SAP BusinessObjects Analysis for Office 1.4 Excel add-in as this has both available a 32-bit and 64-bit version.
Regards
Derek