Thanks HD I bought the plastic reels at Walmart for $2.99 each I believe and they come with the screws to afix them onto the top. All I had to do to this design is to leave enough space so that the reel fits at the back of the top piece. If I recall 4 1/4" is the measurement.
There are two kinds, with and without ball bearings. The ones I've bought have bearings in them, the reason for it is when a fish strikes, the tip goes down, when it's completely down, the reel will start unspooling and you can hear the noise the ball bearings makes.
The rigs are for multi species, all depends on what settings you set them and how hard you set the drag on the spools.