Blackberry Pearl to a Sidekick: Good Choice?

So i currently own a blackberry pearl and i hate the keyboard on the phone. The keys are very close together which makes misspelling too common. I got the phone mainly for the texting but turns out it is horrible. I was thinking of getting a sidekick off ebay or through a friend and use this instead.
I have a few questions ,if anyone can help me that would be great!

1- Will a Blackberry Pearl sim card work in a Side Kick sim cards place or do i need to get a new sim card?(main question, most important)
2- Which sidekick has the best features such as games, options, customization etc.?
3- Are there any other phones by T-Mobile that may be better than a sidekick for texting?

1: Yes, but you need to get a Sidekick Data Plan on your account too.

2: None of them and all of them really. Everything you get has to come off the Sidekick Site. You can't pick your own ringtones, upload your own backgrounds, etc. Only the Sidekick Content Site. basic observation though: 3, Slide, or LX. Nothing older. My wife's experience with the Slide calls the slide a Very Bad Phone™ however. LX in her opinion. Personal opinions may vary.

3: For a full keyboard with offset keys and very good spacing between them, the Sidekick LX is the best solution I believe. I have large thumbs and I can use it just fine. I own a Wing because of other needs, but it's harder to type on.

thank you so much. that really helped me out a lot