Before I buy- mod question (thread prefixes?)

[FurryGirl]

Hello, first post. I'm an alt porn webmaster, looking to add a board to one of my sites, and I'm most likely going to go with vBulletin, since I hear it's generally better and more secure than phpBB.

Since I can't view screenshots of existing hacks and mods, I'm going to have to ask the cliche question of, "Does this exist? Can someone make it for me?" (For those of us still on the fence about whether or not to buy vBulletin, it would be cool to be able to see screenshots of mods so we can see what can be done with the board. Just a suggestion.)

This may be covered by thread prefix mods, but let me explain what I'm looking to change, and hopefully someone can tell me if those hacks already exist, or someone could give me a quote on what it would cost to create them. (I can't ask for a quote as a non-licensee, otherwise I'd post it in that forum.)

I don't expect to have a hugely active board, so I don't want to split traffic and posts out amongst a lot of subforums. What I'd like to do is have one main area where all threads are visible, combine all the "sub-forums" in a way that puts all topics on one singular main board index, but with a "tag" prefix (chosen by the author, or ammended by admin), with a threadlist like

[sex] who here likes erotica?
[sex] condom advice
[music] song of the week
[site] rave about the cute new set

... and so on.

This way, people get an idea of what the thread is about, so they can pick what interests them the most, while also exposing them to threads they might like, but otherwise miss in a subforum.

Ideally, it would also be nice to have a drop-down menu that could limit
your view, too, so someone could just read the music-tagged topics if they
so wanted. Still, the default would be to show all threads.

So, can it be done, has this been done before, and if not, what might such a mod cost?

Thanks!