Update: a message was opened with SAP but unfortunately they could not provide a resolution for this particular scenario. They admitted that the eclipse.ini file cannot be updated since it is bundled as part of the installation package. One point to make that I did not make before was that this was being attempted on an Oracle VirtualBox (4.3.10); the SAP HANA contact said he assumed that SAP has not tested this particular scenario, thus it could not be supported.
Resolution: the end result was to abort trying to install SAP HANA Client and Studio on the Oracle VirtualBox but to install it locally on my own desktop, which runs on Windows 7 Enterprise 64-bit with 8G of memory. The SAP HANA files below were downloaded, extracted and installed successfully in the order shown.
FYI: the Studio installation detected that a 64-bit version of Java was not installed so I installed that and then adjusted the User environmental variable JAVA_HOME to point to that new path, leaving the System variable still pointing to the pre-existing 32-bit Java path.
SAPCAR 7.20 -> Windows on x64 64bit: SAPCAR_315-20010453.EXE
IMDB_CLIENT100_80_0-10009664.SAR Revision 80 for SAP HANA CLIENT 1.00
Support Package SAP HANA CLIENT 1.00 Windows on x64 64bit
IMC_STUDIO100_80_0-20007647.SAR Revision 80 for SAP HANA STUDIO 1.00
Support Package SAP HANA STUDIO 1.00 Windows on x64 64bit
jre-7u67-windows-x64.exe - http://www.oracle.com/technetwork/java/javase/downloads/jre7-downloads-1880261.html
Jim Cleek
HP Enterprise Services