the iSonic 133 is a very nice board, you wont have any problem because relatively shorter than the newer models. what you should think again is the gap between your iSonic 133 and the falcon 102.
my experience is if more than 12-15 cm different between two boards' width, you will get a windrange gap, where the big board is already is too big and the small is still not enough big. your iSonic/falcon has more than 20 cm width different - what is far too big.
with your weight i would take minimum around 70 cm wide board under the iSonic 133 - if you planning to have two boards. for three boards 85/75/65.