Just to add, check out http://www.irishrailmodels.com for info on models past and present, and it's worth deciding even now what kind of layout, what kind of stock, and what kind of operations you are interested in
Welcome to the hobby Joe!!
From experience, I think you might find the hornby stuff limiting in time. I'd recommend adding to your track and maybe trying out some peco code 100 flex track and points to grow your layout.
There are some great track plans here sorted by available space
http://www.freetrackplans.com/Layout-Plans.php
Any any questions at all - just ask
It was even less accessible in the castle in the first place tbh, which was half the problem is was getting 25,000 people a year to visit, while a Leprechaun museum in temple bar gets 100,000!
I've got some Peco platform sides I'm going to try out, and then most likely use a printed card for the platform surface (scalescenes, or perhaps Glenderg )
My platforms are too wide for any of the off the shelf options!