Budget pre-amp for computer/office system

(somehow, when I first posted this, the title became "High End Multichannel Preamp?" but not sure how. Re-submitting here with an accurate title. Thanks.)

Currently assembling left over components into a sytem for my office. Will be using the computer as the source/CD player. The coumpter motherboard has high quality SPDIF output. I going to run that into a Camelot Technologies Arthur DAC (latest version with the Swiss 24bit/192K upsampling chip). I've got an old Musical Concepts modified Adcom 555 power amp, and another 3/4 channel Adcom multichannel amp (GFA-2535, I think) laying in the basement. I have a Sunfire Jr. powered sub crossed over to a pair of Mirage OmniStats (will hang on the wall, off the desk) Unfortunately, no preamp. What used pre-amps, available under $400, would people recommend for such a system? Remote control is not necessary, nor are multiple inputs and capabilities. Possible choices (but not exclusive) include:
Forte Model 2
Audiolab 8000Q
Audible Illusion
Old Conrad Johnson, Counterpoint stuff
Audio Alchemy preamp with the separate PS3 power supply
(don't suggest the Adcom GFP 565, I had one and wasnot pleased)

or should I look at passive units (is it feasilbe with this set-up -- 2V output on the Arthur, 89db sensitivity on the Omnistat speakers, 27-29 db gain and 22 kOhms input impedance on the Adcom amps, and room is small at 16ft x 9ft), possibilities include:
the "Ultimate Attenuators" from EVS
Luminuos Audio's AXIOM
Creek (#10 or 12)
Channel Islands

Thanks for the input
You ought to include the Adcom GFP-565 preamp on your list, since it was (and still is) an excellent preamp. There have been several GFP-565's for sale recently on Audiogon for around $300.
Passive F.T. audio volume control is said to be a great passive for $500 new and about $300 used. Any of the passives should work for you in that system and sound much better than active pre in your price range. The F.T.Audio has second set of outputs you can use for your sub and has four inputs for source. I saw a company on e-bay that sells a one input/output passive for under $200 a few weeks back, can't remember what brand name though, you may want to check over there under preamps.
As I said, I had a Adcom GFP-565 preamp and I was disappointed in the sound. Truly mediocre. Switching to other pre-amps revealed alot of detail that I was missing, and really opened up the soundstage. I see no reason to go back to something that was disappointing, and whose failings I know. Time to see what some other peices can do.
I put together a very similar computer system from old equipment (e.g., Adcom GFA-535 II). I'm using the Channel Island Audio VPC-1 passive preamp that sells new here on Audiogon for $249 including shipping from Underwoodwally. Works fine.
The AXIOM is money well spent!. One of the few bargains in the land of over priced audio. Performance far exceeds cost.

$349,,,,,,,,,,,,,,,,,,,,Tubed Pre-amp that will definately smooth out that Adcom Harshness. Also really good imaging for the price. They have a pretty wide selection also.
Why don't you try an integrated amp like a Cambridge Audio A300 v2.0. It has a preamp out so you can use it either way.
You might be pleasantly surprised with the sound. It's only $250.00 new from Audio Adviser.