Any auto parts/Sears store will have a small decent bar type torque wrench. Stay with a name brand and you will be fine (Proto, SK/Facom, Husky, Stanley, Craftsman, etc.).

As for your other problem, you really need to remove the dust shield to make sure everything is lined up (see Mike Ponte's site for details
http://www.mikeponte.com/volvo/timing.htm).

If your distributor is mounted on the back of the head, the large idler gear positioning is not critical. If the distr. is mounted on the side of the block, it is important.

Obviously, the cam to crank positioning is critical in both cases. You can try using a strong flashlight to see if you can get the crank aligned properly, you might be able to see what you need to without further disassy. Cam alignment should be easy. Just be patient, trying to line things up with the crank dampener and lower dust shield still in place is not the easiest way of doing this. It may very well take more time to do it this way than to remove the crank pulley & dust shield and do it right.