Soldato
Looks good nice simple idea, only other thing i looked at was the MSR Minworks filter.
The MSR filters are rubbish tbh. On the Pacific Crest Trail, our MSR failed and several other people had theirs fail. We ended up using the Katadyn Hiker Pro which worked fairly well. A lot of people also used the Sawer Squeeze which looks like a really good (and cheap) option, especially for occasional use. There is some complaints that the Sawer Squeeze bags aren't very durable, but you can adapt it to fit Platypus or Evernew bags.