"1. What kind of time is required on average?
2. What kind on tools and extra things do I need?
3. How difficult is it to complete?
4. What is a good kit or is it better to buy in parts?
5. What do you recomend?"
1. If it's your first time, it will take about two hours realistically, three or more if you are meticulous and want everything done correctly. Five minutes is an overstatement. I could probably do it now in about an hour.
2. You can use a screwdriver, but having a universal male/female molex remover tool makes it alot easier.
3. It just depends. It's relatively easy if you do a quick job and don't care about how everything looks (but why do this? If you don't care, why would you be sleeving in the first place?)
4. As far as tools go, I bought the kit from CaseArts for $30, but I could have done it by just buying a molex tool. The rest of the tools are basically what a small screw driver or pair of tweezers could do.
As far as sleeving goes, it would probably be better to buy a kit first, then order what else you need. Since this is your first kit, I would advise getting two kits, as you might mess up, requiring a redo. Also, you get more heatshrink. Most kits do not provide enough heatshrink in my experience.
5. Really any of the sleeving kits are good. It's really a personal preference. I've had luck with the Xoxide and Performance-PC's kits, but they are all basically the same thing. Just get the cheapest.
But in the end, my first job took me about four hours total of meticulous work. And yes, it can become frustrating, especially when removing the P4 and PCI-E connectors. That's what the main source of trouble for me was. Also, many modern PSU's have those molded SATA connectors, which do not allow you to take them off. So basically you have to use gigantic sleeving on them. It doesn't look bad, but it doesn't look great.
So it depends on what you want to put into it. Personally, having done it a few times, I'd say it's worth paying the extra $50 to have it sleeved, but hey, that's just me.