What kind of specs am i looking for in an oscilloscope?

and do you connect it to the speaker output to set the gain like you would with a multimetre??

thanks for your time im pulling my hair out trying to find info online

im looking on the net and some of them say that the input is - 20 to + 20 volts, now if 1000 wrms is 63.2 volts @ 4 ohms (using a multimeter) does this mean i want the mother of all oscilloscopes?

 

Velleman HPS10SE Personal Scope 2MHz 10MS/s Special Edition Velleman HPS10SE HPS 10SE HPS-10SE
This is the scope I have, and it works great.
And the price is FANTASIC.

Only downside is it needs 5 AAA batteries.
Or you can get a ac/dc plug, but batteries are the way to go when using it on cars.

Also try getting your hands on the Autosound 2000 disc#104 (level setting)
Works wonders and helps take some of the quess work of setting gains.