Lin and Larry Pardy have a seawater spigot on Talisen that is the epitome of simplicty...a spigot located below the waterline. Just turn it on an you have seawater! Of course it is a little lower than the sink, but no pump to worry about!
Super idea, seawater without a pump! I hate new holes in the boat. But I can think of ways to occasionally fill a bucket for rinsing dishes for example. A ''T'' valve off an existing thru-hull would be one. I do that now, one branch to engine and one to A/C-Heat.
But to answer your question I would choose a foot-pump for the uses you are probably planning.