How long is a piece of string? Why cant you go for both? Most younger people on a lower income or with higher family expenses will most likely buy for cf at first, and then when their income increases they can start to afford the -cf of a cg property. As they approach retirement they will switch again to cf investments.
cg and cf is also pretty fickle, whose to say which properties will necessarily have cg in the future? one persons cf property is another persons -cf due to tax brackets, depreciations scheduals etc etc.
Find out as much as you can about both, and any other information you can get your hands on, and then go and see what you can borrow. This figure will usually help determine the type of property you buy.
Good luck