It is unfortunate that a previous poster didnt get good service from Skyforce as my experience with their Skymap was that it is a fabulous bit of kit!
Its very comprehensive feature packed dead easy to use large screen. I wouldnt heisitate to recommend it.
I also had a problem with a unit they sorted with no problem cost me £80 but threw in a free database upgrade. As the retail cost of the database is £85 I thought it was a good deal.
The black & white model is@£450 +vat from Harry Mendeleshon's brilliant value.
I liked it so much that I upgraded to a colour KDM150 linked to a KLN 94
Have fun