Tsunami 120 vs 125 (older version) vs Manitou?

My 9 year old was bored in the middle seat of the canoe so we picked him up a 10’ Perception Prodigy. He loves it and I’m excited to get my first flat water kayak. We’ll mainly hit lakes and back waters. I’m leaning toward 12-13’ since we won’t be in the open ocean or chop. We may camp on rare occasion. I am 5’10 and 175 and have run whitewater for years. I briefly demoed a Tsunami 140 and have sat in the new 125. I loved the feel of the cockpit over a few others I tried (e.g. Carolina, Pungo, Dagger boat’s). So my question is, should I pick up a used Tsunami 120 or hold out for a used 125 (hard to find).
ps A few Necky Manitous have been available both the 11’ and 13’. Anyone able to compare these to the Tsunamis?

pps should I consider a Tsunami 140?

Always consider the longer boat if it is comfortable for you to paddle.

Can you wait until Fall? The local paddlers here tell me that craigslist explodes with deals when the kids go back to school.