While the forums were down, I spent some time learning how to mod. With the help of MCP and a very useful video on Youtube, and looking at existing code for examples, I was able to create a mod that does just what this thread is asking for! You can check the new thread I just made for it, or you can just download it straight from here!
I had to use another block ID, since the two types are different enough that they can't share an ID (just like cobble and stone) but I used the existing texture for the bottom of the default sandstone for the new kind, so I didn't have to use an extra slot there.
If this gets incorporated into vanilla, I won't care, as this will just have been good practice. But I can now say with a little more authority that it really WOULD be only a little bit of work, and easy work too, as a beginning modder could do it as his first mod.
Perhaps they should make THREE types of Sandstone, the smooth sandstone you described, but it blends better with the sand, the regular "Sand cobble", and a Pressured Sandstone that is the second image.
I apologize for some lack of proper grammar, my fingers are hurt and it makes it hard to type.
I really do apologise for posting on here, as I realise I'm necroposting.
However, I didn't feel that I could leave after reading all 15 pages without leaving a comment. And that comment is that there are some really, really stupid people out there, and that Cold scope has been consistently well thought-through, balanced and patient in the face of some incredibly silly comments.
That, and I support this.
That's all. Apologies again.