Looking for advice on strategy/rpg game

[El Presidente]

I am planning a game that will be a strategy/rpg mix. It will be turn-based where you control a group of people with different skills/personalities and need to manage limited resources. It is not very graphic-intensive (partially due to lack of skill in this area) but it is quite heavy on calculations and simulating a lot of things in the background.

I have done a little prototyping in Ren'Py and it seems to work out ok. The one thing I am missing is a good way to handle gui. Because there is quite a lot of gui to do, different screens displaying all sorts of info, buttons to click, inventory lists to transfer items between etc. So is there some kind of framework for this? Some similar example available? Some general recommendations you can give?

Ideally I would like to have something like Visual Studio to build the game in since it is so gui-heavy, but being cross-platform is an absolute must so that is one reason I'm looking at Ren'Py instead.

[nyaatrap]

Displaying info/buttons are fairy easy if you learned the screen language. You can find basic instructions in the cookbook forum.
About a sample framework, I have a very simple one; http://nyaatrap.blog.fc2.com/blog-entry-4.html

[El Presidente]

I have looked a little bit into that, but got the impression it would be time-consuming to use when there is a lot of gui to make and also that it does not have very good support for listbox/dropdownbox type of elements. But in this case I am just a beginner and may very well be wrong.

I was otherwise considering this: http://wxglade.sourceforge.net/
Might even be possible to generate gui screens with that and have them working together with Ren'Py.