First, go try them on. The SPKs are much wider than the full tilts. But just go to a boot fitter, and see what boot works best. People on here can tell you how they perform, but I wouldn't rely on them to tell you which boot to get.
The Morrisons have a flex of 140ish I was told by the FT rep. He said they are stiff as hell! The SPKs are about a 90 flex, much softer. If you must have the morrison color scheme, you could get them, and then buy a softer tongue.
if your feet like the full tilts better i'd suggest going for some dalbello freeski boots - they appear to have pretty much the same fit as FTs and the use basically the same technology just that dalbello uses newer and better fabrics and shells. ft still uses raichle technology from 1980 and dalbello has been manufacturing ski boots for ages so they brought a lot of new materials and innovations
... thats what my boot fitter told me about full tilts. so i just got my dalbello il moro in transparent white and it's an amazing boot. i really like the way it flexes and i got an i.d. boot fitted so its got the most amazing feel you can imagine from a ski boot. i highly recommend them since ur about to spend a lot of money on skiboots anyways.
i have spk's as i have a wide foot. i tried, for the hell of it FT and IL Moro just for comparison. Couldn't be anymore different these 3 boots. So go and try on and don't get what you think should be riding as some pro has them, or your mate in the park rides them
And v.bored of hearing ppl sprat about flex this flex that. If your boots comfy that's all you need. I ride my spk's all mountain, park and BC. without a footbed