The Anthem is an excellent siphon-feed airbrush and I like it very much.
The Omni 4000 is also an excellent airbrush but being a gravity-feed it has the advantage of being able to reliably spray at lower pressures, creating less overspray and it is a bit easier to clean because of the built-in color cup.
You would be very happy with either I believe.
In regards to using a credit card online, it is really safer than using it in public.
I don't know what your brother did but I have used my credit card multiple times and although I did have a problem once, there have never been any other troubles. If you use a website that has 128 bit encryption it is very safe.
Do you think it is difficult for the kid working at the hobby shop to write your credit card number down after you leave and share it with his friends?
It is not 100% safe anywhere really and many of the online sellers now ask for the 3-digit code on the back of the card for verification.
If you don't want to use your credit card number online then call the place you want to buy it from and order it on the phone. Do not use a cell phone or a cordless phone though as it is possible that someone could pick up the card number somehow.
Mike
“Wisdom is the right use of knowledge. To know is not
to be wise. Many men know a great deal, and are all the greater fools
for it. There is no fool so great a fool as a knowing fool. But to know
how to use knowledge is to have wisdom. " Charles Spurgeon