One of the things you left out of this discussion is the charge controller, which you will have to have because you can not connect your panels directly to either the battery or the inverter. Let's assume you want to charge your Li batteries at 1/4th C or 200Ah X 0.25C = 50A.
Automatically, you can see that you don't want to buy a lower budget controller that maxes out at 40A. You need one that handles 50+Amps. Assuming you double your battery capacity in the future, you want something at might go as high as 100A, but let's do the math first.
It's common to include a efficiency correction (I call it fudgefactor, or FF) to compensate for lower than expected output of the panels. I like to use 85%. By the way, the reciprical of 0.85 is 1.175, so I use the two, depending on whether I am multiplying or dividing.
So, if you want to put 50A into your 24V battery, including the fudgefacter, the math is... 50A X 25Vcharging X 1.175FF = 1469W of panels. Call that six 245W grid-tie panels.
Look at getting six grid-tie panels. I would shop for them on Craigslist, or whatever venue is local to you. Don't buy panels on the internet that need shipping. Stick with local pickup for panel purchases. I routinely get 4W/US$ with local pickup.
Now, the controller. Take a look at Epever's Tracer 6420AN. It can handle up to 200V. Those are ~360US$ right now. That will handle your needs for NOW. If you want to plan ahead for the future, then buy the Tracer 8420AN or Tracer 10420AN instead. They are pricier though at 460US$ and 560US$ respectively. But, cheaper in the long run if you want to expand later. If you bought four 30V grid-tie panels, you could wire them in one series string, and feed 120VDC into the Tracer. You spend less money on thinner copper wire when you up the voltage.
BTW, I consider the Giandel a lower end inverter. I would suggest shopping some for the higher quality brands like Magnum, Outback, and Schneider.
