Hello ,
After looking at the wireframes I have few queries:-
1 from where we would have themes.
2, can admin decide which theme is free and which one is premium.
3. can user see demo of themes.
4. what payment gateway you want to implement
5. is the site is only to sell theme.
Please clarify the details so that I can easily envision the site like you .
Looking forward to hear from you.
thanks
Shobhit