That's still correct. SB Gold is the most advanced version of SB1, and the only patch/update there ever was for it is the missing map patch. If you don't mind clicking "Ok" every time you start the mission editor, you don't even need the missing map patch.
The only other stuff you might want to download is maps (look for the AllTheMaps packages, 5 .zip files) and any scenarios which strike your fancy. In particular, there is a series of scenarios called Tactics 101 which can be helpful if you're a real novice at land combat. Taking those scenarios apart in the mission editor to see how they work is helpful, too.
Good luck with it - please give me a shout if you run into any problems.