Just to throw in my 2 pence.
As it stands your original post, and therefore concept, along with many of your replies have failed to successfully outline any form of a coherent business idea. This falls down to a mixture of factors but the main culprit for this downfall lies with poor English skills. If you intend to pitch a business, especially a professional business, which relies heavily on customer interaction and high quality customer service then English language skills are an absolute necessity. Thus far this appears to be an area of weakness.
Outside of offering pre-made set ups for load bearing equipment how do you intend to sustain your business? Would you sell the equipment individually through your shop/website? In which case how do you intend utilise the information gaps you're so eager to take advantage of and abuse? Surely as soon as a prospective client views your webstore or visits your shop this would defeat the idea before it even gets off the ground? Or would you artificially inflate the prices of all instore items? In which case you'd very quickly put yourself out of business simply by overcharging in all areas.
You mention a perceived gap in the market later in the thread when it comes to those who have not long entered into the hobby and the more seasoned players. Without any statistical data I'd be inclined to argue that this "gap" which you've perceived simply doesn't exist. Your business idea seems to rely entirely upon a client being uninformed but if someone is going to pursue airsoft as a hobby they will quickly be fed vast amounts of information by one of the most helpful communities I've ever seen in a hobby/sport. Hell a couple of weeks ago there was a lad at my local field who was tweaking a pistol load out but he was struggling to find comfortable locations for his pouches. As a direct result of this he walked away with referrals to a handful of sources for quality battle belts and also suggestions for alternative pouch locations before making any purchases to see if relocating worked prior to spending more cash.
As many have already clearly stated, load bearing equipment set ups are tailored to the individual but achieving a comfortable set up takes time and experimentation. This is an area which your proposed "service" cannot address.
I've no doubt that there are those in the market you might be able to prey upon but the upshot of this is that you will only add to the notion that airsoft is a prohibitively expensive hobby/sport for the majority of people.