Personally I would suggest you take a long hard look at Black-T done by Mr. Walter Birdsong. I have had his finish on several of my weapons and have always been impressed with how well it works for me.
If you want an aftermarket type of stainless finish you could also consider Metalife, which I have also used several times in the past. The first time I have Mr. Birdsong apply his finish to one of mine was a Sig P226 that had already been Metalifed. That experience sold me on the Black-T finish.
Good luck. Once you have done something, please give us an update. Hope this helps some.
I sent a Browning Hi-Power to Tripp Research to get it Cobra coated. They did an outstanding job and the gun is just beautiful. I could not recommend them enough. However, the price of a gun is about 120.00 plus shipping so you would be at about 75% the value of your gun to have it refinished. Although, if you love the gun treat it to something special, no matter who refinishes it.
I had it done in November or December of 2006, have carried the pistol daily since then (and sweated like crazy while doing so), and have easily accomplished several hundred draws and reholsterings, as well as several hundred rounds. There is a bit of wear on a couple corners near the muzzle, on the highest point of the slide lock lever, and (oddly) on the right forward side of the trigger guard. No rust has occurred anywhere.
I am happy with it. I can't say it is better or worse than the others since this is the only pistol I have had refinished, but I think it is a decent finish.
If I had your Firestar and really liked it, found it reliable and all that, I would refinish it. In fact, I would prefer refinishing in black (or another subdued color) versus getting a nickeled or stainless finish.