$299? If you went real cheap, ebay, and refurb, then yes, no problem...
A little more and you could have a very nice HTPC...
1.6Ghz Duron -
$39
MicroATX nForce2 Mobo -
$53
256MB DDR Kit -
$68
AIW 9000 Pro -
$135
40GB HD -
$66
16x DVD -
$29
Stylish MicroATX case -
$37
Total - $427
That's a pretty nice setup IMHO, the AIW is what makes it really great, it comes with an RF remote and nice software like EASYLOOK to make using you HTPC realy easy (as in my wife uses it and doesn't complain). And for $30 bucks more you could add the DVI -> component adapter to get HDTV out of it... If you have and old hard drive or optical drive laying around it could be even cheaper, and you don't need to get the nForce2 mobo, or the dual channel kit, that could save you a few bucks too...
BTW, I'm not critizing your purchase, if it works for you that's great, I'm just saying that if you want the aquarium to run on your plasma, this is what I would do... Well, have done I guess... Except for the plasma part... I've had the aquarium running on a very similar setup to the one above for months now, and I've
never had one lockup...
Lastly, you might want to try
FRAPS to capture video of the MA... I'm not sure about looping, but if you have a couple hour long video it probably won't be a big deal if it resets every 120 minutes...