Chances for scholarship and overseas U?

[invoker]

Hi, didn't do too well for my school's standards but still hoping to get scholarship (not PSC or top tier ones) to go US/UK to study either computer science or business. I got AAB/C (H1 Econs), A for PW and B for GP. My CCA record is pretty good as I have won many individual titles for sports and am in the national team. Which scholarship would you recommend I try for my results and what are my chances?
Preferred overseas Us would be:
for US --> Carnegie Mellon, UC Berkeley, and maybe LACs(liberal art colleges) like Pomona, Amherst which i know are also very hard to get in
for UK --> Imperial (yeah probably not), Warwick
Going to take SATs this year.
not banking on getting in on results alone as i know they are pretty mediocre but still really want to study overseas. if no scholarship then probably staying in SG (not complaining but i wanna experience overseas independent lifestyle)

Please indicate whether I have a chance for getting local scholarships (perhaps National Infocomm Scholarship? and please give suggestions for alternatives) , and also for each university (to the best of your knowledge) use the following to show my chances: R=reject RE=reach with good SATs S=have chance with good SATs

Be as honest and brutal as possible :? yeah but appreciate the input please help!!!