You can customise your own "Cookie Monster" cake or cupcake from @Sugar Daddy's Bakery or @The Cake Shop and if you want balloons, @BalloonzMania they can customise balloons as you wish

Where can I buy balloons in bulk for a good price?

@BalloonzMania

@BalloonzMania Balloons shops usually, depends on the quantity you need though! I think if you contact them they would help you either offering their helium or giving useful information on where to find some.

Where can I find letters balloons (each letter separetely)?

@BalloonzMania has a large variety of baloons, I am sure you'll find them there

Where can I customize balloons and flowers and have them delivered to my house?

@Crazy Balloons or @BalloonzMania they make the cutest balloons

Where can I buy balloons?

Try @Istiklal Library Co , @BalloonzMania ,

Where can I find cute handmade cards for Valentines?

go to @From the Earth Amman showroom, you'll find a variety of all handmade products beside handmade greeting cards. and they are willing to give a free one every time you buy a gift from there. But i also believe that cards are available in @Al Shalati Bookshop , @Virgin Megastore , and @BalloonzMania check them out.