As you may already know from reading the Papa John's clone thread, PJ uses screens or perforated disks in conveyor ovens. Because of the conveyor ovens they use, it will be difficult to get a crispy bottom crust. Some of the members who sought to get a more crispy bottom crust used pizza stones to achieve that result. You can see examples of this at Reply 596 at http://www.pizzamaking.com/forum/index.php/topic,6758.msg277924.html#msg277924
and the related post that shows that bottom crust at Reply 603 at http://www.pizzamaking.com/forum/index.php/topic,6758.msg278039.html#msg278039
. Another example can be seen at Reply 630 at http://www.pizzamaking.com/forum/index.php/topic,6758.msg283203.html#msg283203
. The advantage of the use of the stone is that it has a searing effect on the crust of an unbaked pizza as soon as the unbaked pizza hits the stone. You won't be able to achieve the same result as when using a stone, or at least not as easily, in a conveyor oven. I am not an oven expert, but maybe if a conveyor oven were set to a lower temperature, say 450-475 degrees F, and the pizza were baked longer, then maybe the bottom crust would be more crispy. But doing something like that would penalize the output from the oven. That might not be acceptable if you are trying to turn out a lot of pizzas in a short period of time.
Your idea to lower the hydration value to get a more crispy bottom crust might seem logical to achieve a more crispy bottom crust but it is likely to have the opposite effect. Making the crust more dense will actually result in more of the bottom heat passing through the crust to cook the top of the pizza. Often the result is that the top is finished cooking before the bottom crust is where you want it. What you really want to achieve is a dough that acts more like an insulator. That way, more of the heat is directed to the bottom of the crust and helps it brown more quickly and become more crispy. To increase the insulative effect of a PJ clone dough, you could try increasing the hydration while at the same time lowering the amount of oil so that the dough is not too wet or sticky and hard to handle as a result. But, even doing that, you would have to find the right settings and bake time for your conveyor oven.
In the U.S., some pizza professionals have been using special disks that are designed especially for use in conveyor ovens to achieve a hearth-like bake that is said to be comparable to what can be achieved in a deck oven with stones. Those disks are perforated and called Hearth Bake Pizza Disks or Hearth Bake Cloud Disks. You can read about them and see what they look like at http://www.pizzatools.com/Hearth_Bake_Disks/30886/subgrouping.htm
. You can also read more about them at the PMQ Think Tank at http://thinktank.pmq.com/viewtopic.php?f=6&t=7773&hilit=#p53040
. Whether the hearth disks would work in your oven, if you are able to overcome the sticker shock once you see the prices, not to mention shipping costs, would have to be tested in your particular model of conveyor oven.
As for the "light fluffy crust pizza", are you thinking about a Pizza Hut pan type of pizza, or something comparable to it but baked on a screen? PH has several stores in Pakistan so you might already be aware of the pizzas PH sells in Pakistan. In the U.S., PH uses frozen doughs for most of its pizzas although it is possible that they are still using fresh doughs in certain parts of the world. In PH's case, they typically get a bottom crust that is crispy by using a lot of oil in the pan. That has the effect of "frying" the bottom crust. Of course, that is not possible with screens or even disks. Maybe you can describe more fully what you are looking for in a "light fluffy crust pizza". In a broad sense, one usually uses a highly hydrated dough with an above-average amount of yeast, with modest amounts of sugar and/or oil (and maybe none at all), and maybe an oversized rim, and a high oven temperature, to achieve a crust that fits your description.