As far as I'm aware, both the port and IP address are server CVARs:
PHP Code:
new Handle:port_cvar = FindConVar("hostport");
new port = GetConVarInt(port_cvar);
new Handle:ip_cvar = FindConVar("hostip");
new String:ip[64];
GetConVarString(ip_cvar, ip, sizeof(ip));
To get them in the format you want just use the Format() function:
PHP Code:
new String:srv[64];
Format(srv, sizeof(srv), "%s:%d", ip, port);
I haven't tested the above, but I hope it helps!