Concrete will be best, but you will have to properly compact the soil, lay the proper sub-base for drainage, have a vapor barrier, and pour the correct concrete mix atop the above. If not, you may end-up with a floor that looks great but slowly allows moisture to penetrate your new concrete flooring and rust your appliances. In other words, seek and install a properly engineered floor to save you years of potential grieve.

All LVP is actually waterproof. It's a very solid option for basement flooring because of this. That being said though, remember that you should never leave water sitting on your flooring, whatever that flooring, for weeks on end. The water won't damage you LVP, but it will eventually seep through to the bottom floor and gradually cause damage and become a huge insurance problem. You can measure against this though with the installation of a moisture trap depending on your situation. Another thing about LVP, is the option of ER or Embossed in Register. With ER, the texture of the plank matches up perfectly with the register or the original graphic. This means that every grain is captured in detail, including wood knots. An advantage of this is increased surface area so it protects against slipperiness and you from falling. Here's the main link I used to learn about ER and LVP if you'd like more information. I hope this helps!: https://www.reallycheapfloors.com/blog/the-best-flooring-for-basements/

Finished concrete (like epoxy) or porcelain. Nothing else is in the 'water proof' category. Rubber flooring will work (with a horrible smell and HORRENDOUS price tag) but it has been known to soak up mold if it gets wet. Sheet vinyl will work for the dumbbells. Your requirements will prevent you from looking at other products. You will need to pick a #1 requirement and then shop for that ONE requirement. You will choose the product that best fits all the other requirements. For instance, cork is great in basements but is not water proof. It is great for denting...but it will dimple. Etc. As you can see it fits many things but not all. Pick #1 concern and then find something that kinda/sorta/maybe fits your other issues.

OK...point #1. If any part of your slab is 'below grade' the ENTIRE THING is graded as 'below grade'. Personally I would pick different flooring for the 'wet' rooms such as the bathrooms and laundry. The reason: 'water proof' flooring is expensive. So WHY pay for the entire basement to be covered in 'water proof' when only a few hundred square feet actually 'need it'. The other thing is: a floating floor is really all you want to play with. Tiles in bathrooms/laundry room can be adhered to the concrete, the rest can be floated. The basics for ANY floating floor is the same. You must have a vapour barrier (not always underpadding) and you must always have a WELL PREPARED concrete slab that is flat (no wonky subfloors for a floating floor...ever). A laminate floating floor and a vinyl floating floor and a cork floating floor (and even a linoleum floating floor) all require the same thing. And the mechanism to install is always a 'click-together' system. An engineered hardwood can be floated but it almost always requires glue on the seams. Again, all of the same PREPARATION is required. So go ahead and start paying for the concrete slab to be fixed up so that your flooring of choice can be laid down as soon as you can. The 'nightmare' the sales guys are talking about relates to installation and moisture. They are TRYING to get you to purchase the product THEY NEED to move. Yep. I would hazard a guess that these guys have been given 'targets' to meet and/or they have been offered bonuses for moving a certain TYPE of product (too much in the warehouse is costing the company TOO MUCH money). In a nutshell, the reason why you are getting 4 different opinions is because you spoke to 4 different salespeople with 4 different 'company agendas'. That's it. There is no mystery in that. My questions for you (if I were your sales person): 1. What is your budget (do NOT fudge numbers with sales people...it pisses them off and makes them less likely to get the RIGHT floor)? 2. What is your FAMILY situation? Animals? Landscaping issues such as pools, etc? 3. What are YOUR expectations? Can you accept the limitations of certain flooring if it gets you the LOOK that you want for the price you are able to pay?