Poolside furniture takes more abuse than any other outdoor seating you own. It sits in standing water, gets splashed with chlorinated or salt water, bakes in direct sun and rarely comes indoors. Everything in this category is molded from UV stabilized, marine grade resin, so it will not rust, rot, peel or fade the way powder coated aluminium and woven wicker eventually do.
Start with your traffic pattern rather than your square footage. Leave at least 36 inches of clear walkway between the coping and the front of any lounger so wet feet have somewhere safe to go. Sectionals are worth the extra planning because you can add a piece later instead of replacing the set. If your deck gets full afternoon sun, pair seating with a cantilever umbrella or an in ground umbrella mount so the space stays usable through the hottest part of the day.
Resin furniture is heavy enough to stay put in normal wind but light enough for one person to reposition. Cushions are ordered separately, which lets you refresh the fabric in a few years without buying new frames.