angel will do remap and fit CDA for about 475, which is a fair price, what more they come to you which is even easier! your looking an increase of around 15hp and 17LbFt as well as really improving throttle response and thru gear torque
i wouldnt be as bothered about an exhaust system just yet, they add more noise than anything really. remap and CDA tho are a must, the CDA does add a little noise but not too much, and its more a nice sporty noise than anything
as for brakes, best bet (on a budget) would be set of stock disks and ferodo DS2500 pads, if you have a few penny more then put some drilled or grooved (or combi) disks on.
the uprated pads alone will give you a hugely noticable increase in braking power without braking the bank!
ps, if your wanting even more power from the engine a set of cams and remap will add up to 24hp to a stock engine, maybe up to 30 (being positive) with a CDA... this costs a lot more tho!