Anybody know where I can get these modular adapters with the RJ45 socket on
the side rather than on the end.
I have some terminals where the 25 pin serial port is under the base and
there is insufficient clearance to use the normal type of adapter.

In my not-that-recent career managing datacenters I got lots of good
use out of HP Procurve managed switches.  My limited experience with
the mass market stuff was less than flawless.  That was then, this is
now.

I assume I don't buy these at Radio Shack and don't feel like
bothering a sales rep at Prixim.  What does a pair of these things
cost?
http://www.proxim.com/learn/library/datasheets/TeraBridge2_dtsht_YD4-0805.pdf

I've got a network question for you all, hope you can help. I'm
designing a network, and I have four buildings that I need to get
connectivity to. The buildings are laid out in a sort of upside-down U
shape, with the closest building to our main switches about 600ft away.