You can stay around Bt. Bintang area. There are a number of reasonably priced hotels like Novotel (Jln Alor), Sg. Wang Hotel, Capital Hotel,etc. ( can be found onthe net)....all within your budget of around 140rgt.
Most of the areas to visit can be found in the "visit KL brochures" found in hotels.
If you are adventurous, try Kuala Selangor, for very good and cheap seafood and visit the "fire flies" or "kelip-kelip" as it is called in malay. Well worth the experience.
You need to Q for tickets to go up the towers...
Go to Times Square. THere is a huge theme park there. I just got home from there....my head is still spinning but the rides are reallllly good and worth the money!!!!! Rm20 for the whole day!!!! unlimited rides