They're both great motors and you can't go wrong with either one, but which one is best depends on how you use the boat and how much load you carry. If you just fish with a couple of guys, the 130 would be fine and probably burn less gas and the boat will ride a little better with less weight on the transom. However if you dive with 4 guys, 8 tanks and all the dive gear as I have, you might want the bigger motor!
You're right to be concerned about weight, as these boats are relatively narrow beam compared to newer boats, so they definitely are weight sensitive. I originally considered a 115 when I repowered in the spring of 2006 to minimize weight and fuel consumption. I probably would have gone that route had they been available, but the V-4's didn't start production till about June of 06. Now with almost 5 years of usage, I'm not sorry I went with the bigger motor because I've ended up carrying a lot more people/weight in the boat than I anticipated. The V-6 has so much mid-range torque to get on plane that it's not a problem. I've done a lot of long range cruising at nearly 4000 lbs total weight, but with a 15x15 4B prop, it jumps on plane instantly and will plane at 12-13 mph. (The 150 is actually 165 hp at the prop!) The I-Command gage displays % throttle opening, and I never use more than about 45% to get on plane, and cruise at about 37%/3700-3800/27-28 mph. With 2 more cylinders it's also a little smoother.
As an engineer, I like to look at HP/cu. in. as an indicator of how heavily the engine is stressed. Back in 1975 when I bought my boat (with no motor on it), the choice was between a 115 and a 135 V-4, based on the same 100 cu in powerhead but with different exhaust tuning. An old mechanic that serviced the commercial kingfish fleet in Jupiter said a 115 would outlast about FIVE 135's! He said those guys would buy a new engine ever year; he'd prop them to turn max rpm, but they'd go out and load up with 1000 lbs of kingfish and lose about 1000 rpm, lugging the motors and blowing powerheads. He converted them all to 115's and no more problems. He said the 115 would take that kind of abuse, but not the 135. I ran the 115 hard for over 30 years and never had a problem with it, which is why I started out looking at the new 115's which are now rated at the prop instead of at the powerhead as they were in '75 (My old motor was only about 90 hp at prop.)
On the new motors, they have 3 different ratings for the 2.6L V-6 block - "150"(165), "175"(180?) and "200"(200?). On a HP/Cu. in basis, the 115 V-4 is about equivalent to the 175 V-6, so I'd say the 130 is equivalent to the 200 V-6. I suspect that the 130/200 have porting that's tuned for high rpm, so they might actually have less mid-range torque than less "hot-rodded" motors. Those new V-4's have a variable exhaust port area however, so maybe they're optimized for both mid-range AND top end. Would be interesting to compare the HP/torque curves for the 2 motors; BRP published them for the 150 and 225 in sales brochures, so you might ask BRP if that info is available for the V-4's. BTW, check out this excellent owners group forum
owners group forum \ It's got tons of info on these motors, which seem to be excellent by the way. I've had zero problems with mine in almost 5 years and over 300 hrs.