Sigh!!!!....I had to let a 7.5 gauge gas powered SW1500 and 4 gondolas go when money was tight...I always drooled over having something like that in the backyard...You can get stuff like that around here but plan on spending $25,000 on just an engine in 7.5.(type "live steam" in eBay search, I still do that from time to time). You can save a little if you have a machine shop and can finish it yourself, But my better half won't let me spend $10,000 on a kit.
But I am lucky enough to have a steam powered 3.5" to ride on. I just need to build some rolling stock for it.