I've just been playing around with the PC and software side of things on my own project these last few days. It was quite frustrating but I think I've got there in the end.
I have a separate Star Wars.ini file with Gamma set at 2.0, Beam at 1.2. I think the Beam will depend on your monitor, just play around with it till it looks good. Default Mame.ini settings suck for all vector games, but you can get them to look nice and bright if you play with those two settings.
Regards PC specs I had two boxes to play around with this past week. The first was a 2.9 GHz "eMachines 4034" box. I had this as favourite to run Star Wars smoothly with that kind of speed processor (Pentium 4). But it slowed to 65% on destryoing the Death Star and the sound stuttered like mad.
Then I tried a second box with only a Sempron 1.99 GHz processor. This was much better! Speed dipped to only 95% on destroying Death Star and the sound didn't skip so I'm happy with that. Both machines were running Windows XP (fresh installs on each) and both had the same onboard Radeon Xpress 200 graphics. The Sempron box did have 1.0 Gig RAM as opposed to the 512 MB RAM in the Pentium box. Both machines seemed run the game at 100% with no Frameskip just fine... until the Death Star sequence. But on a dedicated cab you can't have that sequence screwing up! I'm still surprised at the box that won out in the end though.
EDIT: Just for info purposes I also have two other machines which I tried Star Wars on.....
1) Intel Core Duo E8500 @ 3.16 GHz with Windows Vista, Radeon HD4850 and 3.0 GB RAM. Games runs about the same as the Sempron. It does very slightly drop speed at Death Star sequence with no sound stutter. I'd say it's slightly better than the Sempron but when you factor in the cost the Sempron still wins.
2) Intel i3 530 OCed to 4.0 GHz with Win7, Radeon HD5570... blah blah
Yeah... no flaws whatsoever. It laughs in the face of the Death Star at 100% without a flinch. Just thought I'd add this in for completeness