CR-18s are good, but if you're looking to use narrow tires, the rims run a little on the wider side. The M13II is another good basic rim, though I'd classify it as a lot narrower than the CR-18.

Regardless, is there a particular reason you're going for 27"? On a lot of older bikes designed for 27" wheels, there's enough travel in the brake pad adjustment to use 700c wheels. There's nothing fatally wrong with 27" (I still have some fantastic, original 27" wheels on my old Fuji), but given the much more limited rim and tire selection, all the new wheels I've put on old 27" frames have been 700c. If you do go 700c, I've had very good experiences with the Mavic Open Sport, which lies somewhere in between the CR-18 and M13II on width, though I think it's typically a bit more expensive than the Sun rims mentioned above.