I've used a Katadyn Pocket Filter for years and years. It's bloody good - can even remove the colour from red wine. I reckon the Katadyn Expedition would be exactly what you need.
What you most certainly won't need is the price tag. My pocket filter cost about $300 about 30 yeas ago and it's still going strong and only on its second "candle" and it gets a lot of use. I guess you get what you pay for.