That Predator is a $2800 kayak… I’m guessing that is out of the OP’s price range if he can’t afford a regular boat.
The size of the lake isn’t really important, the amount and type of traffic that it gets is what is important. I have done most of my fishing out of a kayak the past few years as my fishing buddy has gotten busier with life. I tried fishing big lakes for a while, but since I live in the metro area, almost all the big lakes are overrun with pleasure boats/DBs. I have heard teenagers in their parents’ wakesurfing boats announce to their friends that they’re going to attempt to flip me. I once had a marina worker spot me from a long ways off and attempt to drive over me in a rich person’s triple outboard boat into 40 degree water. That guy was so intent on flipping or spraying me that he went at least 100 yards out of his way and up into an area that normally has hazard buoys because it is so shallow and has huge boulders, but ruining my day was more important to this guy than making sure he didn’t wreck the customer’s boat.
If you’re dealing with that kind of people on a regular basis, it just isn’t very enjoyable to try fishing. I am not a paddling expert, but my best solution to dealing with that type of thing is to point my tip directly into the waves and hope I can float on top of them. Generally with the wakesurfing boats you’re going to get over the first wave and possibly the second, but you will be getting wet. I saw you want a sit on top, mine is actually sit inside though so your strategy may be a bit different, the top on mine does a pretty impressive job keeping most of the water out. With a sit on top though, you’re going to have scupper holes to drain any water that gets inside, where I have to eventually get out and dump the water that has built up in the bottom of mine.
Once I accepted that there was nothing I could do to change the attitude and behavior of strangers on the bigger lakes I started concentrating on the smaller lakes that might be inaccessible for the larger boats as well as lakes with restrictions that don’t allow gas motors or lakes with 10hp or less limits. Doing that has lead to a lot less stress while fishing and much more enjoyment. You may still encounter a lakeshore owner who believes you’re illegally fishing on “their” lake, but they just aren’t used to seeing anyone on the small lake they live on. I had a few people on my favorite small lake try damming up a creek to prevent me from fishing the lake, but I just get out and break it down each time I go. They stuck to building it back up for quite a while, but eventually they gave up.
In terms of kayak, I went with something inexpensive but that looked decent to me. I would avoid the really cheap, flimsy feeling ones that you sometimes see at like Menard’s. I got a Perception Sport Sound 9.5′ sit inside. I like to keep fishing as late in the season as I can and I really like the fact that at least my legs and some of my torso are protected from the wind. I do end up wearing my rain bibs to keep my clothes dry from the paddle drip though. My kayak has no rudder or pedals or any of that stuff that the really expensive ones have, but like you price was a concern for me when buying it. The other thing is that those fancier kayaks are going to be extremely heavy compared to a simple paddle powered one. That would be a big concern if you’re like me and go fishing alone most of the time. I also don’t have to worry about going into water that’s too shallow, as I said earlier, it may take the homeowners a while to accept the fact that they don’t own the lake, so you may end up having obstacles to avoid which don’t slow me down much at all, but if I had one of those expensive kayaks it could cause some serious damage. Another consideration is that in Minnesota, boats 10′ and under do not need to be registered, that $2800 Predator is 13′, so depending on Wisconsin’s laws you may need to deal with registration and those annoying stickers that refuse to stick to anything.