Sampling and guitar

Ideally, you'd want a proper sampler like Kontakt. To start experimenting on a budget, though, the bundled Cyclone sample player could be used, although it's limited to a maximum of 16 samples. Still, you could record 16 chords - that would be enough to cover the basic chords in a given key over two octaves (e.g. C, Dm, Em, F, G, Am) without transposition.

With any sampler, you can only get reasonable-sounding transposition over about 3 to 12 semitones, depending on the register. Higher notes/chords can be "stretched" further than low ones. Add in variations of expression and you end up with lots of samples. Consequently, commercial guitar libraries tend to be quite large. For example, Shreddage, a library that does only one thing - metal rhythm guitar over a couple octaves - is over a gigabyte in size.

You'll also have to edit your wave files so that they are all the same volume, as well as trimming them to the right length, editing out extraneous noise and possibly adding fades. It sounds like work, but it's actually a lot of fun.

Now, as to what "16-bit sound" is, I haven't a clue. Maybe you mean applying a bitcrusher plugin? You don't need a sampler to do that, you just record your guitar part and throw Alias Factor into the FX bin.