I think I need them to be 10 foot wide 4 foot high. Can I have 5 rows of 10x4 panels?
IG panels are generally intended for vertical mount. Because of baffles and construction materials, some of the horizontal mount panels need to be removed for winterization
I have the 4X8s from these folks
Aquasol Pool Solar Panels Wouldn't hesitate to install them again.
I was constrained on size like you. I have 6 panels on a 26ft run of roof. My vacuum breaker is at one roof edge and the outlet of the last panel is at the other.
I have roughly 192ft
2 of panel for a 20X36 Grecian pool in SW Indiana. Makes a big difference in maintaining temp during the swim season. I never have a problem keeping my pool in the upper 80s from Memorial Day to Labor Day. I usually shut it off at 87 or it will get too warm. The water coming out of the returns after running through the panels is often warm enough that it feels good sitting on the steps by the return.
A solar blanket is a huge help on the ends of the season. I generally have mine on in May and September, but my panels let me do without it during the swim season which is really nice.
Solar heat works to keep the water warm during the edges of the season, but you find that the cooler air temperature cuts down on swimming. The pool feels great, but it's too cold when you get out.
You could do stacked panels with 2 or 3 in each row. You'll want to get an accurate measurement of the area to see what you can do.