Custom L2TP/Ipsec Client

We are looking for a custom L2TP/IPSec client software for windows 7/8/10. The client will use a preshared key along with normal credentials and OTP which will be sent to the already established VPN server. Prior to showing the user a connection form the client software should perform several checks: - Is antivirus installed and updated within the past 7 days - Does a file name in a specific location exist - Does a specific application exist in the uninstall registry key The above can be specified directly within the code at this time, we will reference externally at a later date. The client software should allow the user to enter a server name, username and password with the option to remember the server and username but not the password. The .net client will ideally be built in c# and the solution source provided with documentation on the functions implemented. This will then run to a road-map later on of features we would like to add.