You can have dual intercoolers but its completely pointless unless you're running BIG power and/or BIG boost.
It won't really make the turbo more "Laggy" like people have suggested. Turbos shift massive quatities of air a second, so increasing the path by a realistic amount doesn't really affect this noticably.
On a side note, lag isn't actually what most people think it is, i.e. waiting for the turbo to "come on", this phase is spool. Lag is the time between being on boost and being on full boost, usually not a problem on a road car.
You're cooling will of course be improved but you will lose boost pressure between it leaving the turbo and it entering the engine due to the extra obstacles it has to pass through. The second IC won't have to be in direct airflow as the charge will be cooled sufficiently by the first cooler. As long as SOME air gets to it it will be fine.
I don't know how large your IC's are, but commonly, dual ICs are wide but not very tall IC's stacked on top of each other, with boost pipes splitting and entering both.
To sum up i think the idea is totally pointless on your road car as it won't increase performance noticably, may reduce drivability and will be a waste of time/money. The best idea for you is to buy a single uprated intercooler and use that, it will be more than able to cope with what you have.
Ic's fitted in series:
Note the car above runs 900 to over 1000bhp so twin Ic's are feasible. Anything less doesn't need this cooling. Stick to one, thick cored front mount. I cannot find a picture online of the stacked type of dual IC's but look at the above picture, imagine an intercooler identical to the horizontally mounted one attached above it with a boost pipe entering each, then on the exit a single combined pipe.