Electric Guitar Samples

Okay, so here's the deal. I've got a Shure SM57 vocal/instrument mic. I want to buy some relatively cheap home recording software. I'm thinking of either Sony Acid Music Studio or Cakewalk's Sonar Home Studio. I play both acoustic and electric guitar, and sing as well. So I need something with powerful multitrack recording capabilities. I also have a friend who plays keyboard, so I might get some use out of him. I'm into audio sampling and making mash-ups of songs. So it also needs to have some sort of beat-mapping feature and tempo and pitch synchronization. I'm planning on running it on a laptop, if that makes a difference. Does anyone have any suggestions on which one i should purchase? Or if you know any other software that would be better, feel free to recommend it. I'm relatively new to this, so I could use the help. Oh, and a library of pre-made loops and virtual instrument sounds would be nice to. Thanks.