Bucket because you can fill it where water level is low.
The type depends more on support in your area and availability of type rated pilots and mechanics. 350B3 or 407 or 206L4 are all good choices. Also B212 is a consideration!
Fixed wing also if there is a big lake nearby but I would always want to have the fixed wing just to supplement the helicopters. The helicopters big or small will usually always move more tons of water
pr/hr to the area than fix wings.