>>10203684If you want to model a BIG operation, N scale will be the better bet because you can cram a sprawling industry with lots of tracks and cars.
HO scale will be bigger but so will the buildings and the availability of models will be bigger, too. I'll have to dig the pictures up but I visited a layout where the central industry was a fully built-out Bethlehem Steel complex (all the Walthers Steel Mill kits plus some scratchbuilt stuff) and I want to say the whole shebang took up maybe a 12' x 5' area, including the four track interchange yard.
Another large industry that would be much less space intensive but can be 'weighty' is the ore industry. Look up the Splitrock Mining Co. railway on Youtube, it's a freelance HO layout that simulates moving iron ore to ore docks. Iron Ore is such a specialized commodity that it has half-size gondolas to handle its density that would otherwise overload conventional hoppers.
>>10203909Really, anything from Bachman as a 'starter/beginner' locomotive will do just fine. Though I'd recommend hitting up a train show as you'll get far better prices as those things are not worth $100+ as I've been seeing them go for at local hobby shops.
If you're careful, I'd go so far as to suggest stepping right up to Spectrum. My first HO steam locomotive was a Spectrum 2-8-0 that came loaded with DCC and it was maybe about $150 about a decade ago. It's been a smooth runner that's never given me any problems aside from the tender being far too light (though I think that's intentional so a sound decoder can eventually be put in there).
