Word of advice... don't take the year off to do an RA. Most applicants don't have much research experience when they apply. If you are coming from a state school, you are better off taking the year and doing an accelerated Master's degree at the best school you can get into and simultaneously reading Chang/Simon & Blume inside and out. You aren't expected to know any CS in most programs and you wont really need it until later econometrics courses and the ABD stage but you can teach yourself whatever you need to know at that point. Strong math and stats foundation is key... a background in computer science and (sadly) economics are marginal useful in the first years courses.