I would recommend starting cheap with whatever you get, whether it be toys, beds. Cats will ultimately do whatever the hell they want. It kind of sounds like she's already picked where she likes to sleep, but maybe she likes options too.
Even somewhat standoffish cats like mine want to be around. So, maybe a small cat tower nearby. I had one like this for a long time:
http://a.co/4IgOhCz Whatever you end up getting, make sure it's something you're ready to donate or toss if she doesn't like it. If she likes it and you feel like it's worth it, you can always upgrade to something higher quality down the road. You don't want to plop down a lot of $$$ for anything that'll elicit that cat look that says, "I though you knew me."