Odd swim training advice question....

So... I've been working on my swim stroke over the past couple of months, concentrating largely on improving my body position in the water and my "catch". I've made some very good swimming progress. I hadn't swum in my wetsuit since last season. I just got a new wetsuit, and took it for a swim in the pool last week to try it out. I did a couple of warm-up laps, and then did a couple of 200's in the wetsuit. WOW! I was FLYING (for me anyway) - 200's in under 3:15! One thing I noticed, though, was that my triceps were fatigued by that effort, moreso than when swimming without the wetsuit. I figure one of two things is going on with the wetsuit on: 1) The suit puts me in a better position in the water to swim the RIGHT way, or 2) the suit is giving me a more effective catch, so I'm pulling more water, and therefore fatiguing my triceps (kind of like swimming with paddles). Possibly a combination of the two...Which brings me to the advice-seeking part of this post... I'm LOVING the speed in the wetsuit, but concerned about the tricep fatigue. I worry that over distance I might burn out. So, what would be the best way build the tricep strength I need to take advantage of the awesome speed I seem to gain in the wetsuit? Swim in the wetsuit once or twice a week (at the water temps in my pool, I can't keep the suit on very long, though - I'd get too over-heated)? Start swimming with paddles? (Dare I say it?) Lift weights? Other options???Thanks!