U might need quite a bit of crop with a 200mm - 300mm range. ( but of course really depends on how far certain subject )
The last time i got along an old manual focusing 600mm as well as a 70-200mm, and there were certain times i wished i had a teleconverter with me.
If u use telephoto range often then it pays to get a better lens. If not, budget and not occasional use, may i suggest sigma apo 70-300? It can be bought for 180-250 in BnS section and 360 for a brand new one. But if u want a good one, an L lens but u have budget and dont use often then i think u better rent one.
Everyone will tell you diff stuff. You gotta think about what u want.