What type of transformer should I purchase?
You need to get rid of switch-mode-power-supply as a filter. You will be looking for a 50/60Hz (or just 50Hz) transformer with E-I lams and made from silicon steel or steel. 

The pictured ones appear to have ferrite cores and will only work with a complex switching power supply circuit. Here is what a typical one looks like: 

We, in North America, anyway, normally call these 'power transformers' for historical reasons. 



As you say, you'll want about a 9-10VAC output and rated for at least 1.6x the current you expect out of the 7805, assuming a full wave rectifier.