A couple of things strike me here:

You don't say where you're from. Are you a U.S. citizen? You'd need three visas for this trip: Bolivia, $100 for multiple entries; Paraguay, $65 for multiple entries; Brazil, $100 for multiple entries, although you are entering only once. In addition to those, Bolivia requires a copy of a certificate for a yellow fever vaccination as part of the visa application. Brazil requires the same upon entry if you've recently been to Bolivia. Do you have time to take care of all this red tape? They are added expenses too. You say "ouselves," so it's not just you. This will be a lot of extra cash to fork out.

Thirty days is a very nice length of time to get to travel (lucky you), but this strikes me as a lot of moving around. Some of these overland trips you're talking about can be kind of long and tedious too.

Don't discount the effects of altitude. Cusco (11,500 feet), Puno and La Paz (12,500 feet), Potosi (13,500 feet). It can take its toll. Rushing around is not something I'd ever do at elevations like those. Plus, you are interrupting this with several days in lowlands in the middle of your trip. That might be a good thing, but are you going to have reacclimatize all over again when you come back to Potosi and La Paz at the end of your trip? Reactions to these effects are so individualized that there's no way to predict.

I've heard good things about Enjoy Bolivia, so I'm sure they could put something together for you. My first trip to Bolivia, I traveled for three weeks and made the arrangements entirely on my onwn as I went along. I had a blast, and it all worked out, but I speak Spanish well. (Not many English speakers there.) But it might be nice to have some of the arrangements taken care of for you.