The hair on you upper body isn’t all that coarse, based on what I see in the pictures. I would say Lightsheer for the upper body. I have been treated with the Lightsheer on the chest, back, and upper arms and it is the best machine overall if you have type III or lower skin. I works best on finer hairs. Even your forearms are relatively light skinned, and much hairier, compared to mine. The Lightsheer should work very well on your upper body. I have had no issues with patchiness from the Lightsheer, but I have an outstanding practitioner! For maximum effectiveness, the Lightsheer should be used with compression. It makes a huge difference in effectiveness.
What I said above would also apply to your upper legs, above the knees. For your lower legs you should get good results, without scabbing, using the Coolglide. The Coolglide CV would be preferable with its large spot size and high fluences. The large spot size also means less patchiness. This will shorten treatment times while still providing effective fluences. The Lightsheer would probably cause scabbing on your lower legs so I would avoid that unless you plan on wearing long pants all the time. I have been treated with the Lyra-i, a Nd:YAG similar to the Coolglide but with a smaller spot size. I had zero scabbing and post treatment redness with it. I have had two treatments with it and about a 40-50% hair reduction. I tried The Aurora RF/IPL on my lower legs and my skin was too dark as the test spot caused a burn.
I have not tried the Comet as nobody around here uses it. Hopefully Manataray will reply to this post. He has had very good experiences with it. The Comet uses RF and diode laser. The diode laser can be used up to 50J. The Comet does appear to be promising for finer and lighter hairs and for use on darker skin. If you had to limit yourself to one machine the Comet may actually be your best choice. For your upper body they would use less RF and more diode laser. For your lower legs they would use more RF and less diode laser.
The Comet is the only machine of the 3 that has any chance of working on the bleached hairs if you decide to remove those too.
All three machines are great for hair removal. The Comet is promising but I have not used it. Mantaray has and he can be of more help with that. From my experience the Lightsheer is best on Type III skin and lower and the Coolglide is best for Type IV and higher.
Here is a good perspective on the different lasers, but realize they use the Lightsheer in their practice:
Laser Comparison
Hope this helps.
Be sure and keep us posted on your progress.
RJC2001