Thanks for the advice everybody.

There's definitely a couple of things to take away from here. I've discovered since my original post that 'reasonably powerful', in regards to the laptop, actually means 'might work'. It's not guaranteed they'll be able to access the VPN, so I think the Express and SSMS on each approach is going to be easiest to work. That will also limit any damage if somebody inadvertently drops something. As I said, I'll be using a small database that I've created so no serious damage could be done. Nobody should be writing DROPs, INSERTs, DELETEs or UPDATEs anyway but you never know.

The classes will be pretty small, the group I'm training are largely shift workers so there's a limit to how many will be available at any time. I'm also going to be constrained by how many laptops I can get. I can say I'll be able to get one definitely and that's all. Hopefully I should be able to get a couple more but only two or three at most. To be honest, a class of four is the most I'd fancy training any way. I'm neither an experienced trainer nor an experienced SQL user so anything more than that would be a struggle I think.