I like, use, and own several different makes and sizes of torque wrenches. Sturtevant Richmont torque wrenches are my favorite for price, performance, and durability. They sell repair kits for the ratcheting mechanisms, they have interchangeable heads, and they are everywhere. I just did a search and on eBay alone, there are over 100 items listed. Put in "sturtevant richmont torque wrench" and you'll see.
I am a strong advocate for using torque wrenches where Plastic, Aluminum, Stressed Members, and Safety is concerned. I do folks say they don't need or use one, but I won't build or assemble without one. Getting those connecting rod caps to 14 (K) or 17 (F) lbs/feet is critical. Getting the nuts on my tire pressure monitoring sensors to 35 inch/lbs, my windshield brackets on my ST1300 to 30 inch/lbs, my fork caps to 14 ft/lbs - all are critical. I use them on my boat to torque the engine mounting bolts to 55 lbs/feet - the perfect torque to prevent cracked fiberglass and gelcoat and exactly what the manufacturer recommends to ensure proper attachment.
Two things to remember once you have your wrenches -
All torque wrenches are best/most accurate in their "sweet spot" range - the middle. I prefer to have at least 2 - one for 10~75 lbs/feet and one for 50~150 lbs feet. I also have one for 5~50 inch/lbs that I'll use in delicate applications where electronics or windshield plastics are being installed.
If you buy the "click-torque" type (my favorites), there will be a handle that you tighten to adjust the preload. Do Not leave that preload on after use. Always remember to loosen the preset back to zero so you don't leave the spring under tension.
One last observation, I do like the torque-click type wrenches the best. My one and only digital screen got broken when I dropped it and was a pain to see in bright and bad light so those are on my "no" list. The beam type are ok if you have room to fit your head directly over the beam/numbers to read the scale each time. 90% of my bolts/nuts are where I can't and don't want to fit my head, so that is why I like the click-torque type. Just a little practice and you'll both feel and hear when the torque is reached.
Best Regards, Gordon