I would recon you theme forest because it has large collection of theme in every niche..they have html and wordpress thems...and if you need good bundle package then for for elegant themes..
In terms of all round support and security, I think WooThemes are probably the most stable. They are well established, and although the themes can be a little dull at times, they are set up in such a way that even the newest of WordPress users can make their way around and do some customizations.
I ended up ditching Thesis because I hated the fact that the little hacks you could do with EVERY OTHER THEME couldn't be done because Thesis is built differently.
themeforest having good collections of different wordpress theme, if you are looking for premium theme than go for responsive theme that will help you a lot.