IPhone 4s? Straight Talk Plan?

I'm currently wondering whether I should get an iPhone 4s or not. I currently have an iPod touch 4g, and a cheap Metro PCS qwerty keyboard. Is there any way I can transfer my number from metro over to Straight Talk? Plan on buying the phone unlocked from ebay or craigslist for about $200, as AT&T's plan is too expensive for me. I also plan on using straight talk on it, so I will be paying around $45 a month. Also, since Straight Talk only works on GSM phones, will I have to buy a specific carrier model such as AT&T? Or can I just get a verizon/sprint model and still use the straight talk service? I'm really confused about that. So my question is, would it be worth it? I'm not really interested in the iPhone 5 at all.

Don't get straight talk they will disconnect u, if your usage on there network is alot, you need to go with NET10, i have had they used my phone and use close to 2GBs of data and they have not cut off my line.

I have heard alot of storys about people getting straight talk and there service being cut off because they used over 200 MBs?

Straight talk is attractive they even have yearly rate plans. But the best option for the iPhone 4s is to go with Net10

What you need to do to make this work is buy either a AT&T jailbroken phone or buy a factor unlocked phone. Then you have to buy a sim card from straight talk to make the phone work on their network. I think that its 10.00. After that I believe that there's a app you download (straight talks app) that sets your phone to use the straight talk network.

Verizon/Sprint's Iphones will not work on straight talk. They use CDMA and you can't, even if the iphone is jailbroken by you, or Apple, use it CDMA. The only CDMA network that is pre-paid that uses the Iphone is Virgin Mobile but you have to buy the phone from them. You can't bring your own phone to there network.