Being a Sussex resident with similar interests, I feel I should be welcomed to the group too. I moved to the Sussex coast nearly 18 months ago. I have just completed a railway round the garden. It is almost at ground level most of the way, although a sloping garden means it is roughly a foot off the ground nearest the house. All the track is reclaimed from my last line in Bromley Kent. Alas the new garden is not quite as big. I can, for the time being, get down to put stock and locos on and off the track. From building work in my house I had a large number of bricks so the design used all these as the foundation for the railway.
I have three different types of German railways. Largest collection is 750mm narrow gauge, Meyer, VIK, VIIK etc, I have some HSB and other metre gauge stock, including the T3 railcar, although I was impatient and bought the early red livery. I do not mix the two together so I run either 750mm or metre gauge. Recently I discovered 7/8ths, 1:13 in Germany. I like it because I run small cheap diesels. I think I have enough(too much LGB). The 7/8ths locos have a bought chassis with scratch built plasticard bodies. They are battery powered radio control, ideal when I don't feel like cleaning the track. 45mm is a very flexible track gauge. When it gets too much carrying the LGB locos and getting down to clean the track, I think the railway will become a Feldbahn with battery powered radio controlled locos, German of course, O&K, Schome, Diema etc.
It is a wonderfully diverse part of the hobby and there is a wealth of knowledge on this forum. Good luck with your line in Crawley. l hope it provides years of fun.