There's a number of cable parks in Thailand but the best by far is Thai Wake Park. It's just outside of Bangkok and it's an awesome park with tons of features. They even have places to stay on site for cheap if you want to stay and ride for a few days. It's about 45 min outside of the downtown area but it's only a $15 or so cab ride if you want to commute.
There's also a cable system in Pattaya (south east of Bangkok, cool beach city) or in Phuket (famous touristy place).
As far as places to go.. Bangkok is cool but it's a big, loud, noisy city - it's not a beach resort. Skyscrapers and shopping malls. Lots of temples and cultural things to see but I wouldn't spend more than a day or two to see the sights there.
Phuket is touristy but cool, lots to see, awesome views up and down that coast. Good food, kickboxing in the big stadium was fun to see. Can find some surf depending on the time of year... there's tons of different beaches out there. The cable park is near some waterfalls and various elephant/jungle tour type places. Marinas are near here if you want to take a trip to Ko Phi Phi.
Ko Samui / Ko Panyang / Ko Tao are must see's... the airport is on Ko Samui and you can take ferrys to the other islands. Best beaches, laidback atmospheres... just unreal. That's where I would spend any non-wake time if I were you. I remember there was a wakeboard charter company on the north side of Kopanyang but I didn't end up checking it out.