I weigh 260 lbs and ride a Tarmac Pro. After popping some spokes on the Ksyriums that were stock. A few years ago, I had Colorado Cyclists build me a set of CXP 33 rims in 32/36 with Ultegra hubs and DT spokes. Pretty standard build from their website. Absolutely rock solid, never been knocked out of true. Probably 12-15K miles. You know the saying, light, strong, cheap...pick any two! I went with strong and relatively affordable. Also run a set of stock 32 spoke Ultegra Open Pros on my steel Allez frankenbike and they as well have been solid and stay true. These can be had pretty reasonable online but the CC build is pretty bomb proof for me. Stiff too. I run Gatorskin 25s on front and 28s on back BRW. Decent ride quality IMO.
Try to negotiate some $$ and put it toward a build! Good luck.