Big four or MFE?

Sorry for the impending essay....

I've recently graduated from economics at a UK target uni. However due to illness during my degree I had to take time out, didn't do as well as I should have and didn't manage to get any relevant work experience/internships. I still ended up with a 2:1, but there's some pretty bad grades on my transcript and I graduated two years late. So all in all my CV is pretty horrendous right now and I stand no chance of getting to where I want to be.

Ideally I'd like to get into trading, but I'm passionate about the markets and would be very happy to break into anything market related just now. Equity research or Asset Management would be great.

The only possible options I see right now are go for something easier like big four, get my ACA, study for the CFA on the side and try to land something like an investment analyst role from there.

Or I do a MSF, I wouldn't be able to start it till next September though so that would give me a year gap between undergrad and grad school with nothing particularly impressive in between. I'd try to land a summer internship before it but I don't imagine that will be too easy a year after graduating, even if I am going into further study. Plus I'd be even older before I finally got a job. I'm 25 now, would be 27 when I finished the MSF. Recruiters will already be asking what the hell I've been doing with my life, never mind when I'm going for my first entry level position 9 years after high school.

Which of these options would people suggest? The big four route seems to make more sense as it's probably about time I just got on with life and accept that things didn't work out the way I'd hoped. I'm still hanging onto the idea that a MSF might be able to actually help get me to where I want to be though.