I have seen many industrial/electro-ish bands that play live using a laptop running a sequencer software that plays rhythms, effects, background noises, background synthetized instruments, etc.
I know, from what I've seen, that they use the laptop out conneced to the input of an external sound card.... The microfone for the vocals is connected to the sound card input as well. Then, they connected the soundcard output to a mixer. Everything is equalized in the laptop, inside the sequencer software. It is also possible to add effects to vocals inside the software too, so the vocals can also have a different effect in different parts of a song.
I would like to know, what should be the minimum requirements and configuration of the laptop to be able to play live like that, and for it to run smoothly. I have a PC configured and stuff, where I record, and make music, but the thing is that I don't know ANYTHING about laptops, so I am asking for help.
I would like to know about a laptop configuration that is not the most expensive, only to really be able to play with it live, together with a band.
Also, what kind of sound card would you recommend me for that (at least 4 inputs and 1 or 2 outputs).
Thank you in advance!