Note that I plan to turn wireless networking off so I'd be happy if it doesn't work. Also, I don't care about the screen performance. I figure these are the two most likely areas of compatibility concern, but the SSD has me a little concerned, too.
The HP has drivers: http://intellinuxgraphics.org/documentation.html
The Dell can be ordered with either an Nvidia or Intel chipset, the nvidia shouldn't be a problem and it looks as if the 4500MHD it can also come with is similar to the X4500HD, http://en.wikipedia.org/wiki/Intel_GMA which I understand the same Linux drivers above support the G45 Chipset which both of those belong to.
Your (any) os is oblivious to the fact your drive is SSD. That's not say the fact you have one may or may not be an issue, search the web for some issues surrounding their use...
jlc