yeah, many do use the 24/0 for vegging while probably more use the 18/6 or 20/4. personally i use the 20/4 but have used 24/0 for many years. i found very little difference in the plants but a nice savings on the elec bill going with the 20/4.

temps...shouldn't ever exceed 95. it does happen however (air exchange fails for whatever reason) and all's not lost. they will recover from short term exposure to high indoor temps (they handle extreme outdoor temps much better). optimum temp should be anywhere from low 70's to mid 80's with the cooler end during flowering, if possible. the plants will do ok anywhere above freezing but they tend to pause in their growth when temps stay below 45...

there's a lot of info around the net for environment of your grow space so try a search at www.overgrow.com (FAQ's). i'm sure you can find other ideas that would work in your set up.

good luck