Looking For Home Recording Help, Best solution to start recording? Options

[TacoMan]

I've done some extensive searching and reading in regards to the best USB interface/software solution and can't seem to figure out the best path.

I have been playing acoustic guitar (primarily rhythm) for 15+ years. I am looking for an interface that will allow me to lay down guitar and vocal tracks -- and then perhaps add other tracks such as percussion. I have absolutely no experience recording so a lot of the info that I've read regarding features and specs goes over my head. Since this is new to me, I prefer to spend only a modest amount of cash.

Should I go with an interface such as the Edirol UA-25 or Tascam US122 (or other) and then add free/inexpensive recording software (e.g. Audacity)? If so, which interface and software?

Or, should I invest a little more and get a more complete package such as Lexicon Omega, Mackie Spike, MBox, etc? Are f these products more than I will need for my purposes?

Thanks in advance for your advice and recommendations.
Taco

P.S. I will most likely be recording in Windows on a PC.