Larger plastic panels are available and work well for combined access lightweight yet strong, no corrosion worries. Make sure it's reinforced for ceiling use. People like the versatile heavy plastic ones that come in multiple sizes. One solid choice is this durable line https://www.amazon.com/Access-Panel-Drywall-Plumbing-Durable/dp/B085617TBL?tag=contractorhub-20 (check size variants) impact and UV resistant, easy clean, and flush mount with good hinge action. Simple press-in installation, paint to match, and provides ample space for HVAC or pipe work without sagging.