2in1, 1.Can you play X Box live on dialup? 2. How much is it for both map packs in COD: MW2?

I'm getting an X Box Elite in about 2 weeks and I'm wondering a couple of things. ChainedXVeteran is going to be my gamer tag so check me out. I will have great Halo Reach map ideas and my friends already appreciate my help so if you want ideas to uild just compliment or send me something.