in regards to the temperature of the water, it really doesnt matter, as long as its not boiling or anything. cold is fine, remember these are spores, supposedly they survive all kinds of environments. so cold is no problem for them.
spring water, if it is microbe free, should be fine. i used controlled bottled spring water several times with no problems (usually i just used a syringe to extract it so i would avoid opening it too much to air). just make sure you are getting it in sterile conditions. if in doubt, use distilled water, or water boiled several minutes (ideally should be 30mins iirc)...