I have a hand-held gps and a hand-held vhf radio.
First thing I would recommend before departing is a 30watt fixed Radio.
Your hand held is really only good for about 3-5 miles transmission.
With the type of cruising you are planning, a good vhf can be a very valuable tool.
I used to do long distance cruising on our first boat, a small 25 footer with a simple hand help gps. A garmin gps 12. I still have it and still use it as my main back up.
Of course you will also be using a full set of charts and cruising guides to supplement the gps.