I'm very experienced with tumblr and coding for tumblr themes and beyond. I've played around with what can be done on a tumblr theme quite a bit, and while I haven't made very many for active blogs, I know my way inside and out of tumblr theme coding.
I had a look at the website you would like your tumblr blog to look like, and I can definitely code up something like that for you.
I'm PM'ing you links to a couple of tumblr blogs I have coded myself.