Note: The length measurements are for the metal channel only and do not include the additional length of the plastic hardware.
18 each - 9/16" x 25" (18lbs window)
4 each - 9/16" x 25" (22lbs window)
2 each - 9/16" x 20" (19lbs window)

Thanks for posting. In that case, I recommend checking our our Series 385 channel balance. Does that look about right?
For the 18 pound sash, I'd recommend the S385-25 with a 2430 stamp option. For the 22 pound sash, I'd recommend another S385-25, but this time with a 2440 stamp. Finally, for the 19 pound sash, I'd recommend the S385-20. However, there is no standard option for this balance that can support 19 pounds. It will have to be custom made. I'm going to email you a purchase link and price quote for your review. You can use this to place an order on our website.