[mwebb]

imho
your choices begin and end with the Pico scope OR ATS scopes , but for nonprofessional use the ATS scopes are higher priced and do not have the resolution of the Pico scopes .
for automotive use those are really the only two choices.
imho

Pico has higher resolution and costs less to purchase

you can view screen caps and discussion at the ACE MISFIRE Forums or
autonerdz.com

for viewing various hi speed signals in great resolution , the scopes you mention are not going to do it , mostly because they do not have large buffers ,
i tend to record at 500ms per division on about 2 or 5 MS per second and then zoom in on blips in the captures , Pico will fill buffers until your hard drive runs out of space if you need ... i never do , but the option is there .
you can use the trigger functions but you will miss a lot .

pico has built in software adjustable configurable low pass filters for each channel which allow the use of the cheaper inductive current probes , otherwise RFi will fill the screen with hash.
on a cheaper scope , you could purchase a low pass filter set for a certain frequency ...

secondary spark
is one example of something you will need high resolution to view , even old cars have secondary and primary spark and that is one of the more useful thing to connect to to reveal how the engine is running .
there are limitations.
pressure transducers will help to fill the void left by the limitations of secondary spark .
sounds more complicated than it is , but there is a very steep learning curve - if you have a foundation in electronics and scope use , you will be a few steps ahead on the learning curve .

if your car should develop a CAN or Network problem and you want to chase it with a scope , ATS or Pico scopes would be a good choice .

if you watch craigslist
or ebay
sometimes early versions of the snapon vantage or fluke 98 or the little sun automotive scope are available for a pittance - but they are all very low resolution .
of the three , the sun scope has the best resolution .

they would give you something to start with and learn on.

i can email examples of Pico and ATS if desired , i have posted many examples of the Pico scopes in the Ace Misfire Forums