I would check the syllabus for your course to see which electrical techniques you study. These are the ones you will be qualified in. For example your course probably covers:
- galvanic current
- direct high frequency
- indirect high frequency
- electro muscle stimulation (EMS) - the pads you stick on the facial muscles to make them contract
- micro current
- vacuum suction
Your college / course may of course add other ones such as micro dermabrasion or light treatments etc.
Ask your tutor for clarification. If you have the opportunity to do further brand training then always take up the offer as it is a good thing to have on your CV.
If you are buying an expensive electrical unit then you generally get free training on that specific machine.
Doing the generic unit in your course will allow you purchase from a wide range of branded companies.
If you are just looking to buy a simple unit e.g. Esthetix galvanic/Hf unit then you can buy direct from a beauty wholesaler, you just send a copy of your qualification to open an account.