I have a Carerra Zelos which is used as a winter road bike, in XL size, it was bought as it was relatively inexpensive to see how I got on as I fancied a road bike, now it has no sentimental value but I fitted a 90mm stem to try and prevent lower back pain, this was a Deda Elementi Zero one from
chain reaction cycles and I think was about £16, it's not hard to fit, have a look on you tube for videos, I think with a little tweaking you will have a nice comfy bike, but I would echo what others have said, get out on it, see if you get any aches or niggles and take it from there with regard to getting it to fit you, you will proably end up swapping the stem and saddle, as some sadles can be an instrument of torture.
Chain Reaction and
Wiggle are your friends for parts.