If you want an inexpensive 70-200 the best one in our (Canon's) line is the old 70-200f4 L. You can pick one up pretty cheap. The new 70-200f2.8L IS II is the sharpest 70-200 we have ever made. I disagree about buying the 50f1.8. The 50f1.4 is a MUCH better lens and still quite reasonable. The 1.8 is very fragile. The glass is good but it doesn't take much to break it.
Regarding lighting, umbrellas are not the best way to go for highly reflective objects. The highlights thy cast are ugly. You should buy some straight lights and bounce them off show cards. You can find show cards at the
set shop . For lights I use Profoto and Elinchrome. These are rather expensive but the light is really beautiful. For a starter at lower cost, I know quite a few people who use Alien Bees. There is no sync socket on the Rebel so you will need a hot shoe sync adaptor in order to sync your strobes. Do not use an optical slave to fire the strobes form your built in flash as the ETTL system emits a series of pre-flashes which will cause the strobes to fire too early. You can also use a radio slave, I use and love the Pocket Wizard but they are costly.
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78 Z1R, '08 ZX10R, 2010 BC Roadster S/T, 6M, Stillen G2 CAI, Invidia CBE, Berk test pipes, Painted headlights (180˚Custom), JDM rear fog, B&M short shifter, Stillen front plate mount, stubby antenna, setrab oil cooler, uprev. 337rwhp 254ft/lb corrected!