I'm relatively new to biking, and even newer to know about the details about the components of the bike itself. I have a 2016, 29" Totem bike, with a rear coil shock and a front coil suspension (a Suntour XCT DS HLO 29). From what I can see, it's an older model of this one: http://www.srsuntour-cycling.com/components/fork/XCT-29-5620.html
I generally like the bike and I've had good times with it along these years, but the problem is the front suspension is too basic and has scared me a couple times already, so I'm planning to upgrade it for something better, around $350 - $400.
The problem is I'm not exactly sure for this price range, what should I pick? Should I pick another coil based suspension or should I go for an air-based one? For this price range, are some Rock Shox acceptable options or should I look at some other brands? Can I get something with remote lock for this price range? What features should I look to make a long-lasting investment?
Sorry if the question is too broad, I'll share any other information or details required.