ok so i have a nikon d40x with 18 55 and 55 200 lenses. i use it for landscape and wildlife and i want to get a better range of lenses such as macro and maybe 500zoom! it seems that to get good quality lenses they are not compatible with this body, is this true? now im looking at getting a little bit more professional should i just get a new body such as a d300 then buy quality lenses? or will my d40x be ok with quality lenses untill i can afford a body upgrade?