So exciting that you're getting your first pin!
The LED strips that we sell at Comet Pinball come with three ways of connecting them: a wedge socket, a bayonet socket, or alligator clips. If you use the sockets, you'd take out a GI bulb from somewhere on your machine, replace it with one of the aforementioned connections, and then connect the strip to it. It's very easy. No soldering required. If you used alligator clips, you would clip them to the two lugs of a GI socket from the bottom.
If you want the strip to do what the GI does then connect the strip to a GI socket. If you want it to do what a particular insert does, you can connect it to that insert.
The longest we have is 50 SMD strips...which are 20 inches long, so it wouldn't quite run the length of the machine. http://www.cometpinball.com/category-s/1871.htm
The have adhesive backing so you can just stick them where you want them.
There aren't many ways to go wrong using our stuff, though if you add too many lights you can overload the GI circuit, which would blow a fuse. Then you just replace the fuse. Not a big deal. If you were adding multiple 50SMD strips, it'd be better to keep them on separate circuits...usually the GI for games is made up of several different strands, each with its own fuse.
All of this said, the issue with attaching strips to the side of your game is that they will almost certainly make it impossible to lift up the playfield. Pinstadium uses magnets to attach the lighting strips. You need to remove them whenever you want to lift up the game. If you used Comet strips, you'll have this same issue but worse...since you'll have affixed them to the side of the cabinet and now have to peel them off to get inside.
You might want to check out this thread, which has lots of suggestions for DIY solutions that try to replicate Pinstadium: https://pinside.com/pinball/forum/topic/poor-mans-stadium-lighting
I'm about to go to bed, but let me know if you have other questions. Happy to help, but I think to do this right, you need magnetic strips, and you also need some sort of short cover that blocks the strips from a direct line of sight to your eye. Another consideration is that newer machines (with upper playfields, ramps, etc) have a much deeper side rail area, which allows you to put the strips higher up...casting the light further. Blackout will have a much shallower wall, so you will not get the same spread of light that you would with newer games.