iv bought an airoponic propergater and a water heater... now there in bags in my loft lol dont get me wrong they work very well but the downfalls on them are the size and space they take up for the sake of 40 cuttings you could fit 200 cuttings in thatspace using basic propergaters the maintanance of them isnt good then when they root you have to shock them buy squashing bare roots in to a pot while trying to make sure it stays up rite not worth the sake of a few more days in a basic propergater, i dont use heat mats either as long as its comfortable enough in the room to wear a t shirt the small amount of heat from ur white lights will keep them warm enough,
you dont NEED rooting hormone gel but it goes a long way i would nt bother taking cuttings with out it but i have done and they do root but they take a long time durin wich alot of the less healthier cuttings will die and ur survival rate will be at about 50/50 when it should be about 90/10
dont bother with rockwool its shit takes forever use peat cubes
http://pics.davesgarden.com/pics/2010/03/04/Karldan/3114d0.jpg
there 20 times better i add a tiny amount of ryhzotonic or plant magic root booster to the water that i soak the cubes in but you dont need anything but water with peat cubes and the root from them is always thick and fiberous, btw there more round then cube i just call em cubes