Hi,
HikaShop does not have any conflict with Virtuemart (or other Joomla extension).
www.hikashop.com/support/support/documen...-install.html#errors
If you have a timeout, the best is to use the install by FTP.
HikaShop is now a "big" package so we are using "tar.gz" compression in order to have a smaller package.
Tar.gz takes more time for file extraction than zip, so you can try the zip package but a lot of server have a upload limitation to 2MB, so in this case, the FTP install is recommended.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.