[sdiy] Cheapest good sounding digital reverb?

[cheater cheater]

I have been thinking recently about whether it would be feasible to
have a simple reverb of some sort per voice, and so I wonder if anyone
had any suggestions on a cheap algorithm that could be executed on
inexpensive chips.

what I need from the reverb: exponential decay of ~0.5 second, flat
frequency spectrum @ 22 Hz...22 kHz

instrument: 16-voice

architecture: vcos -> filters -> vca1 -> possibly vca2 (all stages analog)

I'd like to be able to insert reverb after the filter but before the last vca:

vcos -> filters -> vca1 -> rev -> vca2

or possibly after the vco:

vcos -> rev -> filters -> vca

or after the filter:

vcos -> filters -> rev -> vca

or even:

vcos -> rev1 -> filters -> rev2 -> vca -> rev3 -> vca2 -> rev4

The reverb is meant to only "sweeten up" the sound by giving filter
sweeps, transients, and vco sweeps some more substance in the time
domain. I think this sort of thing could easily add a unique sound to
the synthesizer. I know some of you will mention the DSI Evolver, but
honestly I did not think that the digital part in that synth was of
high enough quality. So what I'm looking for is an inexpensive "hi fi"
reverb.

The considerations are either:
A) a single chip per voice/stage which only processes one stage in one
voice. this chip would have to have high audio quality AD/DA, work
without a lot of additional circuitry, just enough processing power to
perform the reverb, and be relatively inexpensive (up to ~5 per chip
at low volumes)
B) one global chip with a bunch of AD/DA. this chip would need to be
able to read from 64 AD and write to 64 DA, each at 16 bit.

personally I prefer A because 1. it does not carry a bunch of digital
stuff around an otherwise analog board which can be a royal pain and
2. drifting clocks (or ones shifted on purpose) will add variety to
the sound. So those two kind of kill B for me.

What sort of chip would you all suggest for version A?

What algorithm would you suggest to run on it?

Thanks.