As i recall the $150 cost to address the heat soak issue in the 192s is a best case cost not an average cost. riva sold 15 on eBay at that price but currently don't have anymore available, at least not in eBay. The one I just saw one eBay is $600, new they are $1,900.
Yamaha stated that the 1,052 hp mr1 ho engines put out 160 hp. To calculate the hp of the subsequent Yamaha engines you have to convert from kW to hp. The 1.8l n/a engines non carb and carb produce 132 kW and 122 kW, respectively. The sho engine in the 192s produces 154.5 kW and The svho engine of the 195 produces 184 kW. The kW to hp conversion multiplier is 1.341 so the n/a 1.8l produce 177 hp (non carb), 163hp (carb), the sho produces 207hp and the svho produces 247hp.
By the way, the 160hp mr1s max out at 10,200 rpms and make a high pitched noise starting at about 9,200 rpm. It's not a noise that is easily absorbed / reduced. The n/a 1.8 liter engines like those in the 190 series boats max at 7,700 ish rpms so the noise noise isn't nearly as bad/ high pitched at wot. Just more to think about when selecting a boat.
@ dalcini, your profile indicates that you already have a boat so I assume you already know that there is more to a boat than hp, acceleration and top speed. That said, I recommend that you not put too much focus on these factors and do your best to test drive each boat you are seriously considering before making a purchase decision, I'd bet many members here would be willing to give you a test ride. Lastly, for the cost of a new 190/195 you could get a really nice used twin engine Yamaha 232 LS and 242 LS if you have to have the reverse arch tower.