F5 SSL Client facing server using HTTP only. Is this possible to use only F5 for Client Cert then translates the port to http facing the server?

F5 LTM is the best for Offloading SSL. You need to create a pool like of apache webservers running on port 80. Create a VIP on HTTPS/443 Port. Before that import your ssl certificate in LTM and create and ssl profile like www.abc.com. While creating VIP Select client certificate from available list. and thats it. :)

This will help you. http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm_configuration_guide_10_0_0/ltm_ssl_profiles.html