unfortunately you didn't tell us where/how you will be using the dinghy
. if in mostly protected waters with mostly short hops to shore and mostly small loads a minimal rollup inflatable with a small 2 to 3.5 hp 2 stroke
will work fine. i had that combo for years. i think i might go one size up from 2.5 m if possible. and that rollup floor really makes it easy to store on deck
if longevity or strong sun is an issue, get one in hypalon fabric
. if it's a two year throwaway, pvc will work and will be cheaper. also get a name brand like avon
or achilles or ab or caribe or a few others that some here will soon recommend.