pc (Mala) to Vision Pro connections questions

[Cartouche]

Hi gang-
I'm converting a jamma/60-in-1 to a Mame w/Mala front end and have a question or two. I'm using a Vision Pro open frame monitor, and my pc is fitted with an older version of the Ultimarc ArcadeVGA card.

Which way should I connect the two? I saw this tutorial here, that seems like the quickest/cheapest way to do it, unless there's some new product or adaptor that's surfaced since then.
http://arcadecontrols.com/arcade_pc2arcade.html

Also, is an isolation transformer necessary with the VP's?

Speakers: It would be a lot easier to keep the 2 original speakers from the Taito cab I'm using, can I just splice the wiring into any PC speaker jack and plug it right in?

Thanks for any help,
Marc