Will an MBA or a Master in Finance from Heriot-Watt further my career or does a school like HW which doesn't have any entry requirements suffer from a bad reputation?
Heriot-Watt is one of the world's better universities. If you think you can handle their program, go for it.
The Edinburgh Business School (Heriot Watt University) MBA is currently ranked globally at 88 by Financial Times and 75th by The Economist. Whether or not a MBA from EBS will further your career, I couldn’t say; even so, your career wouldn’t suffer because of a graduate degree from Heriot-Watt. By reputation … successful completion of the EBS DL MBA program is extremely challenging (e.g., no continuous assessment; all courses are assessed ONLY by 3 hour closed book examinations).