Sorry to hear of your loss. [name_f][/name_f] I hope some of these ideas will help.
[name_f][/name_f]Maybe something like [name_m]Rory[/name_m] [name_m]Christian[/name_m] [name_m]Fletcher[/name_m][name_f][/name_f] for a little boy? [name_f][/name_f] [name_m]Rory[/name_m] meaning red king[name_f][/name_f], [name_m]Christian[/name_m] for the name he went by and [name_m]Fletcher[/name_m], meaning arrow-maker[name_f][/name_f], for his love of bows and arrows? It would give your son a distinct name of his own while linking him to (and following the name pattern of) his much beloved uncle.
[name_f][/name_f]For a girl, [name_f]Scarlett[/name_f] could certainly work, but you can also consider a name like [name_f]Poppy[/name_f]. [name_f][/name_f] Here[name_f][/name_f] is a list of names that mean red[name_f][/name_f] or red-haired[name_f][/name_f]. Also, [name_m]Christian[/name_m] could work for a girl, or any of the many [name_m]Chris[/name_m]- names. [name_f][/name_f] For [name_m]David[/name_m], you could rearrange the letters a bit or shorten/lengthen/slightly change the name to find a name that could work and still honor your brother [such as [name_f]Vida[/name_f] (life) or [name_m]Davi[/name_m] or [name_m]Avi[/name_m] or [name_f]Davina[/name_f] (little deer) or [name_f]Davia[/name_f] (little deer) or [name_m]Davin[/name_m] (little poet) or [name_m]Davis[/name_m] (a surname derived from David; beloved)]. [name_f][/name_f] For his love of bows and arrows, [name_f]Sagitta[/name_f] could work or you could use a name related to an element of the outdoors [such as [name_m]Ailin[/name_m] (forest), [name_f]Sylviane[/name_f] (of the forest), or [name_f]Willow[/name_f] (willow tree). [name_f][/name_f] I think something like [name_f]Poppy[/name_f] [name_f]Vida[/name_f] [name_f]Sylvaine[/name_f][name_f][/name_f] or [name_f]Poppy[/name_f] [name_f]Sagitta[/name_f] [name_m]Davis[/name_m][name_f][/name_f] or [name_f]Poppy[/name_f] [name_m]Davin[/name_m] [name_f]Willow[/name_f][name_f][/name_f] or [name_f]Poppy[/name_f] [name_f]Davina[/name_f] [name_m]Ailin[/name_m][name_f][/name_f] could work.
[name_f][/name_f]Good luck in finding a meaningful name to honor your brother. [name_f][/name_f] Hold on to the amazing memories you have of him.