Feats, Equipment, PrCs for a sneaky bard

[zimmerwald1915]

So I'm playing in a one-shot (it might continue, but it's meant to be one-shot) game this week. The party's light on casting, sociability, and skills, and has nobody with trapfinding, so I'm thinking Bard. The game starts at Level 6, and my DM's okay with giving my bard Trapfinding through taking Planar Touchstone at 6th level.

However, barring that one trick, I'm not really sure how to properly build a sneaky bard that can also be decent at bardistry (that is, advancing Bardic Music and casting, as well as social skills). What would the advancement be for such a character beyond level 6? Straight Bard? What would be the first- and third-level feats (thinking human, no flaws allowed)? What equipment, besides an instrument, thieves' tools, and stat-boosting items would be helpful?

P.S. please don't suggest Spellthief. My DM hates them and goes out of his way to kill them, apart from any other considerations.

P.P.S. I much prefer Bards to Beguilers, purely for flavor reasons. So if you suggest one of the latter, I won't ignore it, but it had better be good.

[Lateral]

Wasn't there a prestige class that advanced bard casting/music and gave Evasion, a Sneak Attack progression, and had some sneaky uses for Bardic Music? I remember 'cause I remember seeing it and thinking, "Hah, 'move, move, move, move silently across the battlefield!'"

[Psyren]

I know you don't like them, but Beguiler is definitely the best choice here. You can even grab Bardic Knowledge(-ish) via Loremaster or Paragnostic Apostle.

[Keld Denar]

Check the prereqs for Subsonics in CAdv. It allows you to use your perform skills below the audible spectrum. That way you can still inspire your allies while moving silently. Alternatively, if you can swing it, spend your 6th level on Mindbender in CArc. It grants Telepathy 100'. The only requirements on bardic music is that the target "hear" you. It doesn't say they have to hear you with their EARS. Thus, you could Perform: Sing inside of their minds. Its a little bit of a stretch, but either method would eliminate the huge neon sign that says "The Adventurers Are Here" whenever you attempt to perform.

Other than that, I'd suggest Melodic Casting as your 1st level feat. This saves you some skill points on Concentration that you can invest in Move Silent, as well as allows you to cast while using Inspire Courage. 3rd level feat should be Songs of the Heart from the Eberron Campaign Setting, as this beefs up your Inspire Courage, your strongest Bard song.

[Escheton]

Kinda wondering what that bard prestige that gives evasion is, anyone have an idea? Would work good for getting into foch' lyrist.

[true_shinken]

Kinda wondering what that bard prestige that gives evasion is, anyone have an idea? Would work good for getting into foch' lyrist.

Spelldancer?