Hi Rich
I have not fished the river in question but i have done a fair amount of fishing in some of the rivers in the south east. If i were you i would take along a 5/6 or 6/7 fly rod and then a small ish coffee grinder with about 7 or 8 pound line on. This way you can chop and change whenever you like, and dont let anyone tell you that a 6/7 is too small for pike, i'v done it countless times. And i love spinning with a fly rod, especially for perch.
A lot of the rivers in poland have a real mixed bag of fish. You can often find trout, grayling, perch, and pike in all of the same areas, however, the poles tend to keep everything they catch no matter how small, and what i have found is that when fishing with the worm all of the above tend to be caught....except grayling..!!


You get a lot of spinning with small rapalas for trout and plenty of guys fishing the worm, but not that many fishing with maggots, so the grayling tend to be around in numbers.
I have often been told that there are ''no fish in this river'' but in the evening i can make out small rises, and it turned out they were grayling (liep-yeng) thats not the actual spelling but how you say it in english. Some of the rivers are big and fast flowing, and i've done some kayaking myself in poland. I can imaging it though being quite difficult flyfishing off a moving kayak...
Rich