If you decide on flags, why not make your own. All you need is a flat board onto which you can make your own shapes - round flags by bending a strip of thin plywood to the correct depth, held together with string round the circumference. Fill this with a concrete mix and BOBs yer uncle.
Square flags can be made using any timber, again cut to the correct depth. The beauty of these are that you can adjust the size of the flags to your own preference, and with the addition of some cement dye they can be whatever colour you desire.
I have tried these before and they do work, all it needs is a little time and effort and a sound base to lay them on
Best of luck-
Never take life seriously....
Nobody makes it out alive anyway!!