Bitscope

The waveform on (most affordable) digital scopes isn't as clean as an equivalent analog scope. They usually more than make up for that in their ability to capture a single event. How well they can do so depends on their real-time sample rate. A reasonable reproduction of the signal requires at least five, or better ten, samples per the highest frequency of interest.

Bitscope's real time sample rate is 40 MSa/s, so a single-shot capture will be acceptable up to signals of 4 - 8 MHz.

It was a great hack when it was first published, but it is what it is.

Instek and Rigol have some good, inexpensive stand-along digital scopes with decent sample rates and PC connectivity. Look there first.

WRT the logic analyzer features, there are some good USB products. They just need to capture edges and not analog levels and so their rates can be acceptably high (e.g., 500 MHz) and still have reasonable prices.

You might find this interesting about the Rigol Ds1052E

What are your requirements? The Bitscope is quite poor value for money these days IMO. See:

Dave.