Switch would you recommend?

Well all I can say is go with cisco for sure, With my experience these other vendors such as dell, netgear, berklin, ect... Cisco has everything down while these other brands aren't nearly as reliable or have as much cabalities as cisco switches do. Its worth the extra $$ for cisco products, i think. We have a few dell and netgear switches in out network and we can tell the difference and they loose connection randomly. Thats what I think in my experience. I'm not sure what cisco switch you should get, but I would get 2 of the exact models with the exact firmware for the best setup but its not necessary. Hope this is some what helpful.

- Joshua Jacobs

I would say go with HP ProCurve units, they're reliable, they're cost effective and very versatile.  The 2800 series would probably fit you quite well with allowing room for future expansion.

Otherwise my second choice would be Cisco 3750s.

While HP is obviously the lesser known both switches are pretty much identical when it comes to features.

-S

Are you trying to do the '500ft' link with copper or did I misread? The 500ft link will have to be fiber.

mgob saw the infrastructural issue in its entirety.
I only told him what switches should I get and he foresaw the degradation issue (which I am currently having btw) -- I thought a more intelligent switch would resolve the issue, but I obviously need to put in fiber backbone!