Replying to Help with buying a canon Rebel DSLR

Im interested in buying a dslr canon rebel and i wanna know what the difference is in the XSi and XTI series? i know theres 2 mega pixels and a smaller screen difference but other then that do i loose and features that i would need? if any? also just looking for a canon cause i currently have a canon rebel EOS K2 35mm camera that i am using for school and i have a pretty nice macro lense for it, so im staying with canon, not sure if i wanna buy the package witht he 18-15 MMIS lens cause my friend has one with his XSI and he doesn use it to often, so i might go for the body only on which ever camera i buy.
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