You want solid core CAT5e cable, preferably plenum rated. UTP just means unshielded twisted pair, which is what most CAT5e cable is unless you specifically buy shielded cable, which might not be a bad idea in your case with the long run you plan on doing, but it costs quite a bit more.
Plenum rated cable (marked CMP) is ok to run pretty much anywhere you want without violating fire codes.
Riser cable (marked CMR) is ok to run in walls and between floors, but NOT ok to run in ventilation areas like heating ducts or areas above drop ceilings which are considered plenum areas.
General Purpose cable (CM, CMG, or CMx) is ok to run only on a single floor.
There's also an outdoor specification, I can't remember what the letter code is for it, but I don't believe it can be used in placed of plenum cable.
And then there's unrated cable, usually just called PVC, which isn't certified for anything.