Hello,
my main problem here is I don't have any GPS device to test the program, but it shoud be not a problem if you have some and configure it to send data to my IP computer. Once said this, I reviewed the specs of FMXXXX protocol and it seems not so much complicated, so I can do it without problems. I have large experience programming with C# and VB.Net, but not so much with Java (even I did some programs with it). Also, I created a lot of SCADA controlling multiple machines, so TCP/IP communications are covered by far.
Please take this bid as starting point to keep talking, bid can be reviewed based on real amount of work.
Thanks for reading!