Advice on converting site please.

I’ve been asked to look into converting this site to Modx: http://www.adventuresinafrica.com
For the most part it seems like a no-brainer, but I’d like some thoughts on certain aspects, specifically this search function:
http://www.adventuresinafrica.com/find.aspx

My feeling is to add Tv checkboxes to the pages and then use ditto to display them, but how would I go about generating the drop-downs (can Wayfinder do this, or will I have to manually create them?)
I would prefer a way without having to add Tvs when new options arise, since that would require me to step in again for the client.

I’d really appreciate some input from the experts out there.

There is a snippet named TVExplorer that can do exactly this sort of specific search.
http://modxcms.com/forums/index.php/topic,16456.0/topicseen.html

I have never used it but if you look at the examples it seems to do what you are looking for.

You can use both ditto and wayfinder to build select menus as well, but I think that TVExplorer should be able to do this for you.

thank you so much!