Mesh Body Addicts is an awesome resource, I'm glad you've checked them out!
Picking a body is largely deciding what's right for you. I recently purchased Maitreya's Lara and absolutely love it. It's a very popular body so there are a ton of clothing options for all price ranges. It was right for me because I wanted to be able to easily find outfits and have a choice of quality clothing. Being able to individually hide body parts via the HUD makes almost any clothing so easy to fit.
Finding a mesh body that will allow you to wear the clothing you already have can be tricky, so demoing was definitely the way to go. That being said, think of your mesh body as an investment not only for the present but for the future. You'll likely want to use it for a long time, so you'll want to ensure when you buy new products you'll be able to find them for the body. Abar's eBODY has support, but it's nowhere near what the heavy hitters (Maitreya, Slink, Belleza) have. Many products rely heavily on appliers, and if Omega isn't working 100% you may want to consider if you want to invest in the eBODY or look into another.
Keep in mind that for many Mesh bodies you can use the sliders in the edit shape area to alter the look a bit. Be warned that altering it too much can result in difficulty with clothing, but it all depends on the individual piece. Lots of mesh clothes come with various sizes.
If you need any more information or have any questions please feel free to ask! I hope I've helped a little.