I hate to answer a question with a question but is your telco provider limiting you to L2 or do you just have the switches and switch ports configured that way? Even if you don't need it now, I would go L3 in case you need to add another VLAN in the future, or if you want to put ACLs on either side.
Of course if the telco is limiting you to L2 for whatever reason then you don't really have a choice. Although I don't know any reason they'd do that, if they are dropping off straight Ethernet. Which, if you have the circuits plugged directly into your switches, it seems they are handing you off straight Ethernet.
$0.02