Configure StrongSwan/IPSec for tunnel to Cisco ASA 5550

We need the expertise of someone who has an understanding of VPN tunneling between a linux box running StrongSwan and an offsite Cisco ASA 5550. We can provide all configuration information you will require to write the configuration file, however testing of the connection is done external to us and therefore is a slow process of sending the file and waiting for the third-party company to reply with a result of the connection in their staging environment. Therefore, we need someone who has a good understanding of this kind of work so that you can easily identify errors returned by the Cisco ASA 5550 which in turn you can fix by making changes to the configuration file of the StrongSwan box.