Will you list the Canon Digital SLR camera models for me, in order?

I am having trouble with my original REBEL 6.3 mp. Err 02, Err 05, telling me the wrong number of pics left to take. Telling me 'card full' when it has just been formatted an is empty. Under the canon loyalty program I can get a REFURBISHED Xs for $319; an Xsi for $399, or a T1i for $419. comes with 90-day warranty. Seems they've changed memory card size and battery size too. At what model did these changes take place? Or should I buy a new T1i with 18-55 and 50-200 for $880. Your thoughts will be appreciated.