If you already have a Linksys router, then I would go with two 8 port gigabit switches for growing room. Just route your twelve connections from the punch down block (PDB) to the switches and then feed the two switches from the Linksys router. Since you are using one port on each switch for the router feed, you'll only have seven open on each for the PDB connections.
Everyone has their preferences, but I tend to stick with Netgear and Linksys. Here's a Netgear 8 port switch on Newegg that is fairly popular and at a decent price.
Netgear switch
