Pretty much comes down to how much you want to spend. Honestly, I think all the options you listed work fine. I do the bare bones pumps and provide my own timer. Half the cost of the next option, but yeah, you have to do a little work. But then, if we didn't like the work we wouldn't be doing this, right?
So if cost is an issue go that way. If ease of use and plug and play is what you want, then go for one of the bigger options. Nobody has ever bought a Profilux doser and said "Man this is the worst $400 I ever spent. I hate the whole world." So really just personal choice.