I second the suggestion to follow the Woody's recommendations. Studs are a great thing if you put them in using one of the standard methods. If you do it wrong, they rip holes in your tunnel and heat exchangers. That being said, here's my two cents worth:
1. Get the number and size that Woodys recommends.
2. Buy a stud hole cutter (about 15 bucks)
3. Follow a recommended pattern for where to put them (ala Woodys website again).
4. Shop around for prices. I've never paid more than $270 for a full set of 144. Full retail is about $400.
5. After you put them in, check them regularily. Bent, broken studs OR backer plates can turn into problems. Either they throw out a piece of metal that will hit like a bullet, or they rip out a pice of the track. NO GOOD ! I check mine every 500 to 750 miles and replace any that are even in question. (Cheap insurance).
6. Keep you track tensioned according to manuf. recommendations. If the track is too loose, you're back to ripped tunnel and coolers.
7. Don't forget to put on proper carbides. (I like Woody's carbides too)
If I have a new track, I put in studs before it's in the sled. If the track is in the sled already, I take out the rear torque arm bolts and drop the rear of the suspension. Then hang the back of the sled about 4 feet in the air so I can get under it. Then all work is done on the track between the top of the rear torque arm and the rear axle. You'll have access to 4 or 5 "windows" at a time, then roll the track around to get to new spaces. (Taking off the drive belt will make it easier).
It normally takes me 3 1/2 to 4 hours to put in 144 (track still in sled as above), including clean up. If you haven't done them before, it might be a little bit longer.
If you've never had a studded sled before, ride it carefully to get the feel of it before going all out. The sled will handle very differently.
Others things to think about - Don't destroy your studs by spinning the track on a road crossing ! If you drive your sled into the garage, the studs will slide, just like on ice without studs, and you'll find you end up in a pile against the back wall of the garage. You remember that shiny new bumper you put on after a trip into the rhubarb last year, well now it has a bit more "character" to it.