I just spent about 2 hours trying to find panels that will fit that are some other cell configuration. The solar panels seem to be either 26 or 39" wide. The 39 are too wide, and if I go with 26", the wasted space causes me to drop from 600w to 400w, i.e. two 200w 26" wide panels vs. 6 36" wide panels for 600w. Due to my ignorance, I don't understand the significance of the number of cells. Seems what matters is how many volts/watts you are pushing down the wire at the voltage you want, i.e. 24V. Seems the more I learn the less I know or understand.try to find 60 or 72 cell panels; I do not know about 33 cell panels; you might go to electrodacus.com and ask this question to Dacian the owner engineer of Electrodacus. my 60 cell 250-watt panels are 39 x 65 inches each. I put the in pairs of 2 and this works great. the newer 72 cell panels have more watts so you may want to get the higher wattage 72 cell panels. I bought 2 pallets of used 60 cell panels for cheap on eBay.
look at Electrodacus.com for his products.