Don't just look at Full Tilt's. Look at a range of other boots and brands. If your SPK's fit well why not looking at getting a new pair of them? But look at a lot of other boots and just try everything. You also don't necessarily need a park boot, rather buy a good fitting all mountain boot that a poorly fitting park boot. Go to a boot fitter and get properly fitted with custom footbeds and any other work needed.
As for flex of the Konflict it uses an 8 Flex tongue which is roughly 125 to 130 traditional flex. Whether or not this is to much for you depends on multiple things such as ability, ankle flexibilty, weight and height.
If you're light and you just like crusing, hitting rails and small-medium jumps and maybe the occasional big jump then the 8 flex tongue will be way to much stiffness for you and you don't need it.
If you're heavy/big/fat or you ski super harder and go huge on everything then 8 flex tongue will be fine. Like if you are constantly taking shit to the thug zone and hitting the biggest jumps in the park a lot then you'll probably like the stiffness of an 8 flex.