There are all kinds of pavers, pieces or stuff in large rectangles were advertised last week, about 18x25 or something to heavy for me to lift in slat look, limestone look etc. Take a tour around a cement & patio place & look at all the options. I installed a small patio of key shaped pavers made of 3 shades of concrete/cement & I leveled area under orange tree, put some sand down, leveled that with 2x4 8 ft wide & laid them in pattern I liked. Only problem is I was short 1 corner piece)( it's by some plants so hardly notice, but get all your materials & check that they are all the same size or will fit the area you want & they are now making the pieces smaller. It turned out nice & I don't get wet shoes going over to turn on the hose. Tree doesn't seem to mind & still has great oranges & if we ever have to dig it out as they don't live forever, I can pull the whole 8x12 patio up. If your sewer is too close to top of ground you would have to go with plastic or wood deck I imagine. Wood decks are lot of work- so I hear from relatives! If you used wood close to ground you could make a door that could be swung up so you could get to sewer & not wreck whole patio.. Good Luck! Go to Patio forum & see what some of them are using. or Google Patio materials & look on line!

Flagstones with pea gravel for spacing between the stones. If you really want a deck, do a platform deck over a frame in sections you can lift off to gain access underneath. You can also do a gravel pad inside a border of retaining wall blocks. You can move the gravel to access up the sewer line if needed.