While you are upgrading your system, consider a gigabit router/switch.
I have two offices, in one I have installed AC4 beta (latest version seems pretty stable). I recently upgraded the computers (found cheap ones with win xp sticker and gigabit networking) so I decided to add a gigabit network card to the server and purchase a gigabit switch (actually 2, one only had five ports but was real cheap then I found another with 8 ports which encompassed the rest.)
Wow, things are much faster. Its like AC database was installed on that remote computer, instant name popup when you type a name in, quick opening of the import items which used to be slow.
Soon I may get around to my other office, but one step at a time.
