What type, English, American etc? Sean Ryan that organises the Toys of Yesterday fair in Bray deals in N Gauge. He could make up a starter set for you as I was talking to him yesterday about an N gauge American starter set I want to put into a coffee table.
You could fit a lot on that space, the trick to track planning is less is more. A layout covered in track won't look like a model railway. A level crossing would be easy I wouldn't use the Hornby or Peco ones as they don't look right. Have a look at my website I have a layout up on it with a level crossing using the studio scale models brass kit.
A 5' wide layout will need access from both sides if you do not have an operating well as you won't be able to reach across the layout. 11' x 5' is a decent size, do you want a double round loop or shunting or a mixture of both?
Peco all the way, had the same problem with a client that installed Hornby points and a tender on a steam loco kept derailing and causing a short. They are absolute rubbish, and for the money you pay they are a rip off. The better modification to them is replace them!
Looks great, the walls embankments and bridges ad a great dimension to the layout. Paudie the bridge, walls, platforms are all made from foam cut with a hot wire cutter. Eoin is a master at it.
Hi Alan, cut up some flex track would be best. I'm building a layout at the moment for a customer and it's 7' 6" x 4'. Because it's small I am spacing the track to 67mm for clearance but I am using all Peco flex track. I had to fit extra pieces of track between the points. Here's a pic