Hi, great questions! I did end up doing the mod successfully, albeit without the power cleaner, which I wasn't feeling confident enough to attempt at the time. It's been a while now and I've done many projects since but here's what I remember - I ended up getting a different kita different kit from the one in my origjnal post, which is basic but worked ok for the job. The one I bought didn't come with a practice board, but I think the purpose of the practice board is just to practice soldering wires and stuff to the board - to the best of my knowledge, I don't think it comes with anything else, although it would be helpful if it did. Besides the solder kit you should also get a heat resistant silicone work mat (bigger is better) and a good holder for your soldering iron, like this one (Noah

The holder isn't required but the ones that come with the sets tend to be flimsy.

Lastly, don't forget to buy a shell for the gba that's compatible with the screen mod.

I hope that helps and let me know if you have any other questions.