There are a lot of choices. From a wilderness use point of view, the case you put the phone in may be more important than the phone you decide to buy. Count on using the phone sparingly and carrying the means to charge it with you. Make appropriate configuration changes to improve battery life -- no matter what phone you have, if you're using "push" notifications from social media apps, battery life won't be great.

There are bad guys in the world who use nefarious means to compromise mobile devices. Mobile antivirus is of very limited utility against these threats. Look for a mobile device manufacturer with a good record of updating software to close known vulnerabilities. Install apps only from reputable developers.