A lot of good advice in here. I did mine myself about 2 years ago. They are not that hard. The hardest part, in my opinion, is popping the CV axle out of the differential.
The axles on my truck were not original. I'm pretty sure they were from NAPA from what I could tell. I ended up replacing them with another set from NAPA. I got the ones with the so called "heavy duty" boots. The lifetime warranty was a plus.
Something to think about. The CV axles will last a long time even with torn boots. I drove with mine torn for around 25k miles. Granted it was only for about a year and half since I was doing a lot of road trips.
To further add to that point, the ones I replaced them with, started to tear about 15k miles after I installed them. I have put on another 18k miles and I still have not replaced them. If I hear any noises, I'll go ahead and replace them under warranty. I don't want to replace them just so that the boots can tear again.
Here is the thread from when I did mine.
"CV Joints boots cracked, replace axle now or wait?"
I probably would replace the seals on the differential when you change them. I didn't and I ended having a leak on one side. Here is a thread for the leaking seal and how I replaced it.
"CV Axels replaced before, front diff seal leaking?"