There is an internal base map in these older units, but its not good enough to navigate with. I think its only valid upto 50nm zoom or similar. If you dont live in ireland or wales or SW england, you will need to buy a chart chip on ebay for your area.
The external antenna is included. It does not have an internal one.
To clarify, everything you need is included so long as you have room in your console to flush mount (cut a hole to mount flush). If you need to mount ON TOP of the console you will need to U bracket which I dont have. You or I can buy on ebay, £15.