Good call on the Optiplex. I did investigate those briefly and (at least the ones I found on Newegg), while they're still for sale (refurbs), they are discontinued. I would like to preserve some minimal amount of "standardization" in my selection because if this works out as well as I hope, then it may transition out of "temporary" and into "permanent," and there may be at least 3 identical systems which could use the same "upgrade."
I found something similar though, A
Lenovo H30-05. I'm not sure the actual tower profile standard but I believe it's a mini-tower; they claim "1/2 the size of a standard tower."
It doesn't have a DVI port, but it does have a PCIe x16 slot into which I plan to install a
MSI Gforce GT610 video card.
It doesn't have serial ports, but it does have a PCIe x1 slot into which I plan to install a
Rosewill 2port serial card.
Both those cards come with "low profile" bracket options.
For the video card, when using the LoPro bracket, you lose the VGA port, which is fine since it has onboard VGA, and I won't even be using VGA.
For the serial card, when using the LoPro bracket, you lose the one of the ports, which is fine since they are on a ribbon cable and I can just punch a hole in the case to feed through the 2nd serial.
I think this will be good. Do you see any problems with it?