I tried to find the best place for you,But I think you should buy it from amazon.
There are many more size with fast and may free shipping for you.
Amazon alway discount their products, you may get better prices than anywhere.
And this is I found in amazon about fabric spray paint and white t-shirts.
Please check this link..
Fabric spray paint...
Hope this help :)
I suggest Blankapparel.ca
They sell the new gildan soft style t-shirt... I was basically designed after the American Apparel 2001, slightly more fitted then their regular boxy shirts and it's also a lighter weight material and much softer like the AA styles. Oh, did I mention the price.. White shirts are as low as $2.28 ea and colours are $3.24
The new soft style sku is 64000 and 64000L for the ladies.
Hope this helps.