Economics at Oxbridge? Advice needed

Ok, so I have decent GCSE results;
Maths - A*
Statistics - A*
Triple Science - A*A*A*
French - A
Geography - A
R.E - A
ICT - Me
English Lang - B
English Lit - B
German - B

Considering the secondary school I went to these were very good

and for my AS levels I got (UMS marks):
Maths - A (283/300)
Biology - A (283/300)
Economics - A (161/200)
Chemistry - B (239/300) 1 mark away from an A, going to get it remarked with hopefully an A!
General Studies - A (166/200)

I primarily would want to do Economics at Cambridge... but have been told I would be better suited to Econ and Management at Oxford. Failing that something science based.

I am considering continuing all four A-levels or dropping Chemistry to pick up AS Further Maths or just doing 3 A-levels and dropping Chemistry

I need advice on what my chances are on getting into an Oxbridge uni to do Econ or LSE, Warwick, Bristol or any other good uni.

Any advice or similar experience would be welcome!

I would not advise Cambridge.
90% of offers go to those offering FM. Your maths score of 94.3% is not especially strong with no FM on offer. Secondly your best three UMS average is 94.3+94.3+ 80.5 = 89.7% This is about the level where you may not be called for interview for Cambridge Economics. Added to this a B in both English exams at GCSE is a disadvantage.
Your Science UMS is 89.4 which is borderline for a NatSci interview & I think the Chemistry would be a big worry.
The average successful Economics entrant has 96%+ UMS.

Oxford & LSE place a high emphasis on GCSE A* score. (It was rumoured to be a minimum of 8A* at LSE in 2010). PPE has a success rate of <10%.
Warwick & UCL expect A*AA with A* in Maths so you should be good for those. Bristol place less emphasis on Maths and your three A s look good.

I think you really should decide on the course first, university second. For Cambridge & Oxford (& Imperial) I don't think it makes much difference to your chances of an offer.

Thanks a lot for the advice, do you think it would strengthen my application if I picked up AS Further math?
also would my grades be good enough for a medicine degree?
And do you think Oxbridge would put into consideration that I am a ethnic minority, from a lower socioeconomic group living in an area of low Higher
Education progression?

AS Further Maths would definitely strengthen your application.

Oxbridge won't care about your ethnicity, but will take into consideration your educational background when assessing your application.

Your grades could be good enough for medicine if you apply correctly, but if you haven't been getting experience related to medicine by now then it's too late.

All in all for Economics at Oxbridge, I'd say you have a shot considering your educational background, but it's probably a slim chance. It's only 1 of 5 applications after all.

Thanks a lot for the advice, do you think it would strengthen my application if I picked up AS Further math?
also would my grades be good enough for a medicine degree?
And do you think Oxbridge would put into consideration that I am a ethnic minority, from a lower socioeconomic group living in an area of low Higher
Education progression?

They will look at all of your application to try to assess your performance in the light of your educational and social background.
For medicine see this:
http://www.study.cam.ac.uk/undergraduate/teachers/presentations/2013/Good_Practice_in_Supporting_Applicants.pdf

I worry that you seem to actually have no idea what you want to study a little over a month before the deadline for the application. All you want to do is get into Cambridge. If this was the case it would make sense to apply for a degree with a much higher success rate than Medicine & Economics. But if you show no real interest in the subject and have no relevant reading (or work experience for medicine) you will not impress at interview.

Your UMS are good and perfectly reasonable as a disadvantaged background for less competitive degrees at Cambridge but there are plenty of applicants from your background who are stronger for Medicine & Economics who are also more committed to the course.

Considering my situation would you recommend Econ and Management at Oxford or Economics at Cambridge?
And regarding Experience i've done:
Volunteering to work with patients suffering from Alzheimer's and Dementia
Brilliant Club in Chemical Engineering
Summer Work experience at GSK Pharmaceuticals
Visited Royal Science Society
Done the NCS Challenge
Been on a marine ecology expedition
Worked at a Electron Microsope Lab at Brunel University
And i'm a anti bullying Cyber mentor
And was deputy headboy at my secondary school and am Headboy at my sixth form

Do you think these are relevant and would strengthen a possible Medicine application?