Welcome reethi!
AS far as your CIPD goes I would agree you need to get that under your belt. I am assuming you started it from what you've said so just the second bit to go perhaps?
Don't know about that particular course, it's been quite a while since I did mine, and I did it at Thames Valley University. Funding then for that course was up front in two chunks, I was fortunate enough to have sponsorship from the company I was working for at the time.
Not paying the fees until after you've graduated sounds a bit unusual, your best bet might be to get a career development loan from somewhere on that basis, rather than ask the university to wait for payment. I think there are some government schemes for that kind of thing but no idea whether you or this course would qualify for them. Bit hazy about it sorry!
Personally as an employer I'd be more interested in your experience than whether you've done an extra dissertation, so if it's easier/quicker/cheaper to do it without the MA bit consider that, unless you've got a fascinating interest in something particular and want to write a dissertation on it...
Particularly if you're going freelance, I reckon potential clients will just want to know you tick the box and are qualified, for reassurance, and an MA isn't going to make a heap of difference to them. Again, it's your experience and skills that are interesting.
That's my opinion anyway, fwiw, and I never did an MA either, hasn't held me back!