If I'm living in a tent for a month, what type do you recommend?

First of all, this volunteer experience sounds awesome opportunity, congratulations. I am writing this answer with a background in hiking and backpacking. I haven’t used a tent on the sand or beach (if that is what you are doing) but I’ll give it a shot. I recently went on an extended trip on the PCT/JMT and heavily researched tents. This answer will hopefully give you enough background knowledge to make an informed decision. If you want to dive into the very specifics of tent buying you can look at the REI resource. Good luck! 
 
When considering what type of tent to buy the main factors that come to mind are: Size, stability/durability, weight, and three vs four season. Most of those are influenced by each other but I’ll go into them. For your specific situation I recommend getting a Marmot Limelight 3 Person Tent. I have the 2 person tent and it works great. I figure that you’ll need some extra space for the long term stay. If you think you’ll need even more space for all of your…accessories and such then I’d go with the Sierra Designs Lightning HT 3 Person Tent or if you are feeling crazy and want to do laps in your tent then go with Marmot Limestone 4 Person Tent.
 
Things to think about when purchasing a tent:
You have to consider your personal preferences: What am I going to use it for? Is it going to be getting mud, dirt, bugs in it? How much rain will it have to withstand? Windy? Do I want a view while inside? Do I want it to be easy to set up? How big do I want it?
 
Size
First thing you want to consider is how big you want the tent to be. You can go from super small single person tents to huge family car camping tents with more stuff than you’ll need. You’ll also want to think about the overhead space that you’ll have. Some people want the least amount of weight as possible so they opt for a smaller interior space but again that’s your personal preference. My guess is that since you won’t be traveling with this tent for long and you’ll likely take it down and set it up a few times that you should get a three person tent for the size and space so its more “liveable.”

Three vs Four Season
This mostly applies to people who are going to be traveling in the snow and places that it’ll rain a lot. 90% of the tents that you’ll see out camping will be three season tents because they are lighter, less expensive, and easier to set up. Four season tents are the ones used for expeditions on snow and that sort of thing. They’ll withstand huge winds and moisture. A good example of a four season tent is theMountain Hardwear Ev 3 Person Tent. You can see it has a lot of anchor points as well as high tension throughout the shell (not sure what the technical name is).

Durability
Some people like to sacrifice durability for weight. These guys will take good care of their tents on their back packing trips and will repair rips when they happen. They won’t go to rough and would rather have a light shelter than a protective cocoon. An example of a super light and less durable tent is the Tarp Tent Double Rainbow. I got one of these for an extended back packing trip and while it was insanely light I found it confusing to set up and your conditions had to be perfect. As long as you take some time to look and invest some money into a reputable name, chances are that you’ll get a nice quality tent.  

Weight
Mostly for back packers and hikers, weight is crucial when thinking about the miles that you’ll have to walk. Since you don’t be carrying the tent around that much I wouldn’t worry too much about weight but it is a factor to consider. 

Why I think the Limelight 3 person is sweet:
-Really easy to set up and take down
-Comes with a ground tarp (pretty much a tarp you put under your tent to protect the bottom)
-Comes with a rainfly that you can remove when you want. You can take the rain fly off for a more ventilated interior or keep it on to warm up a bit and keep the rain out. 
-Extra storage space inside in the form of pockets. Also comes with a mesh canopy that will hold a flash light.