I have several of the lionel thomas related models and several of the bachman HO scale items. Overall I like them but they don't make "show sounds" -- in the fact the bachman model don't make any sounds and have no working lights. I've seen retrofits on the web for DCC sound and led installations on them. It's been on my list for quite some time to give that a try, just you know - all the 10000000 other things get in the way.
One thing I like about the show is many if not most of the characters are based on real engines. I place for that kind of info at the Thomas and friends wiki in the "basis" section (and also in the right side panel).
For example, they are expanding their characters all the time (got to drive new sales!) -- so a new one is called Merlin and it's based on a LSWR N15/SR "King Arthur" according to the wiki.
In the explainer it gives more details: "Merlin is based on the LSWR N15 Class, referred to as the "King Arthur" class by the Southern Railway, specifically No. 783 Sir Gillemere. In 1943, Sir Gillemere was fitted with three stovepipe chimneys by Oliver Bulleid as a wartime experiment."
Kinda cool...
Also Hornby's is yet another source of Thomas related models - but while slightly different scale than HO in other dimensions -- its runs on HO scale track, or this is what I understand.
https://www.hornby.com/uk-en/s.../thomas-friends.html
(note that several of these items say "DCC ready")
