All the bits in that ebay kit are readily available locally, except maybe the manuals, but these are here;

http://www.pinrepair.com/atari/manuals/atari-superman-parts.pdf

http://www.pinrepair.com/atari/manuals/atari-superman.pdf

Read the manuals a few times, don't worry about the electronic details, but get a feel for the position of thing, rubber sizes and fuse locations and rating and the settings thatyou can play with.

It's really not that hard to strip and clean the playfield yourself - as others have said it's very satisfying. Don't get carried away by the level of detail that others go to here - to each his own and you can do more as confidence gand experience grows.

Buy a full set of rubbers, what's needed is listed in the parts manual, some new sleeves for the coils - they are a standard size and slip in with about two screws, a new ball and a bottle of Novus 2.  Get 100 globes - have a look at one, if they twist in and have a nipple and two pins - like a smaller version of what you use in most house globes then use type 47 globes, if they sort of push to plug in then they are type 555. If in doubt post a pic and someone will tell you what sort they are.

Check the fuse values installed - again listed in the manual, just see that the correct amp rating is installed.

Clean the playfield with nifti on a rag and then polish with some automotive body wax.

Ask questions here - there a plenty of people who kindly and generously answer questions.

Do a little bit at a time, take lots of photos from all angles, sketch things that are confusing. Find someone on this site with the same machine and ask them for a photo if you get a bit lost.

It really isn't that hard and is very satisfying and quite fun!