I have an eclipse 3 & a 25 watt heater & it keeps my water temp consistent though out the day & night.
As for cycling cant tell you how long it takes. Ive been trying to cycle mine (fish in) for at least a month now & only 1 so far looks to be close to complete. I am far from an expert on cycling I'm sure someone else can get into more detail. I went out & got the API freshwater master kit. I test my water every day for Ammonia, Nitrite & Nitrate. If my Ammonia is above 1.0 I usually will do 40-50 change under 1.0 I just do 30% change. Basically you do this until you see no Ammonia & no Nitrites & Nitrates 5-20PPM. You will see spikes in all of these esp Ammonia & Nitrites. Just keep up with the water changes. IMO the most import on a fish in cycle is keeping the Ammonia levels safe enough not to kill our lil guys during the process. Unfortunately you just have to be patient. I had figure eh they are only 3 & 6 gallon tanks how long could it take. Well like I said I'm at least a month in.
I know it sounds like a lot of work but in the end it will be worth it. Less water changes & a safer environment for our fishies.
Hope that helps I am cycling newbie too. There are more qualified people on here that could offer more info