Thank you for your inquiry.
I have a lot of different niches available, although for website ranking purposes this shouldn't matter. You are purely using the link juice tumblr provides and google remembers from the old account that used to be in it's place.

If you're however looking to start an actual blog from these, pm me with your specific wishes and I'll do my best to find something that suits you.

I placed 4 posts on 4 tumblrs last night with a backlink to an old blog post on my money site that never went past page 5 in google. This morning I woke up and it has bounced to place 22 without any other links! I'm going to point another 4 today and see how far I can take this.