Hi Abra
A hairstyle with no parting is not a problem.
Looking at your photos it seems like you currently have slicked-back hair with a very fully exposed hairline. That is do-able with a hairpiece, but it is a high maintenance style. You have to make a good job of applying the piece, and any lifts in the lace would be rather noticeable. Getting the hairline right is one of the techniques that some people struggle with at the start. So you will make your life easier if you go for a style which doesn't involve a slicked back fully-exposed hairline, at least at the start. For example, I brush my front hair forward and then flip it up with a bit of gel. That works well, and I think it could fit in with the style you are aiming for.
Because of the heat and humidity where you live, I would strongly advise you to opt for a lace base, and not a skin base. I find normal sweating is not usually a problem even in humid places like Sri Lanka - the adhesives are strong enough to withstand a lot of sweating and still remain solid, and the sweat itself just runs through the mesh of the base and evaporates. But if you find it a problem there are a few possible solutions, including using a medical grade antiperspirant under the adhesive area, or applying a scalp protector - a liquid you brush on your scalp which dries to form an invisible barrier between your skin and the tape or glue.
Your encounter at the salon was interesting. It is hard to believe their profit margins are high enough to justify keeping a whole room full of bald guys just to fool potential customers. Are you thinking of using this salon for your first unit?
Noah