I should just give up for tonight?

I can be good with graphic design and have some learned skills in using programs designed for such purpose. I'm trying to make a book cover for someone, my sister, who is self-publishing her novel. She already supports my one proposed cover but I think I can do better.

Now my different image programs don't want to work together. I'm using Linux - gets everything I want done with photographs but somehow the text tool of The Gimp is lacking and still doesn't let you put typeface vertically displayed as horizontal. Ie, I want the title sideways on the face of the cover in this iteration. I can do that with another program, Inkspace, and create either an svg or pdf but formats wrong when trying to combine the two.

So first, if any of you have experience this way - recommendations before anything. If you don't have advice, I also love the message that says technology is sometimes scattered and when it works, it works, and when it doesn't, it doesn't.

Vent off :)