Beginner Interface, Daw... Options

[T1mon]

There might be some topics about this already but you don't mind writing a little, do you?

I'm a guitar player and want to start to record some of my stuff. (not that it's worth it but it's nice if you can record it together with a drum loop or something like that and to capture ideas on hd)

I would be using a 12" 867mhz Powerbook with 640MB Ram and OSX.
I tried putting my guitar directly into the line in of the PB and then using Audacity to record. As a preamp I use Amplitube Live.
But with that setup I had quite some latency which I think comes from Amplitube because when I play guitar and for example open a window or scroll it takes about 1-2 seconds to do that... not really nice.

So one of my questions is now if this problem would be history with a nice interface? (this one looks nice: M-Audio MobilePre USB

I'm also looking for a nice recording program. There are so many out there and I really have no idea which one to get. I don't need anything professional, it just has to record my guitar and maybe be able to insert a drum loop. (I'm currently using Fruity Loops on a crappy PC but I could get Reason)
So I don't midi.

I hope you understood what I mean. Thx!