Should I sit my entire Maths A Level in June 2013?

Hi guys, after a long search, I have failed to find any help to shed some light on my situation (which may just go to show how outlandish my idea is...).

Finished Year 13 last year sitting on a BBC (pardon the pun), this was not what I expected and did not get me into any of my uni choices so decided to take a gap year, re-sit and re-apply.

The 2 B'S in Economics and Business I don't really have much of a concern about, I feel I've already got them up to an A with the Jan exams that have just passed. The C in Maths however, is giving me nightmares.

I'm on MEI (the private examination board from hell) and I just sat C2 and C3 in Jan and I don't feel I did anything to contribute to a higher grade. I just find the syllabus is so over-complicated in comparison to, say, Edexcel, and I find I run in to so much unexpected material in exams, regardless of how much past papers and revision I do.

I know I will have done little contribution to my grade in Jan, so when the results come in March I doubt the grade will change, it may just be scraping a low B if anything.

I'm seriously considering re-sitting all 6 modules (C1, C2, C3, C4, S1, M1) in June on the Edexcel board as I've taken a look at that curriculum and it all just seems a lot simpler to absorb and be examined in. With edexcel, you learn Maths, and then your tested in the Maths you learn. MEI feels like I learn Russian and I'm tested in Mandarin, such a shock sometimes when I sit down for a paper.

My current module scores on MEI are:
C1-80
C2-70
C3-34
C4-28
S1-85
D1-77

My initial plan was to re-sit my C2 and C3 in Jan, bump those up and then sit C4 and maybe C1 in June to get an A overall. However now, I feel so bad about how my C2 and C3 recently went, I feel to ditch the whole MEI scene, jump on to Edexcel and sit all 6 exams, in an attempt for an A in Maths.

I do in fact know someone who did this (pretty daft fella at that) who sat 3 modules in Jan and then 3 in June on his gap year, and he indeed came out with an A. He couldn't stress enough how much MEI turn everything into an enigma and how simpler Edexcel seems in comparison.

I would be more than happy to put in the time and effort to work hard if I knew my work was going to a worthy cause, but MEI has just disheartened me so much, I feel like resorting to Edexcel is the only feasible option.

I would appreciate any advice, either drawing from experience or not, and if people do advise to go with Edexcel, which modules to go for (don't wanna make my mountain any larger than it has to be).