Google Shopping, look for "beam torque wrench"

Click type wrenches are a lot easier to use if you're doing a lot of fasteners, but the beam type isn't rocket science, and should be available for $10-20 USD or local equivalent. Cheap enough that a little extra at the local auto parts store will probably still be less than the shipping to order one.

A click screwdriver type calibrated in inch-pounds like the FAT Wrench also comes in handy if you ever deal with screws that are likely to strip out, or anything that needs to be assembled the same way every time. Sure, it's $40, but that's often cheaper than stripping out one screwhole in an aluminum part.