silly question

hi
Q1. if i get 2 old flash units & buy these hotshoe to pc sync adapters will they work with my camera eos 20D & 400D.

Q2. i have a 380ex flash what is the cheapest way to add another flash does it have to be an EX series. at the moment i use the 380 EX with a canon hotshoe cable i need another flash so i can get good lighting for portraits, basically all i want to do is connect 2 or 3 flash units to my camera.

if you can point me in the right direction or give any links that would be appreciated.

many thanks

I recommend having a read of www.strobist.com . It is all about cheap off camera flash use. Start in the lighting 101 section.

You questions are very subjective and it depends on what you mean by cheap and if you are looking to use the flashes manually......

Q1: They should work. I'm not sure what max trigger voltage the 400 will handle, but you should find out what the flashes you get have. Some are pretty high voltage.
http://www.botzilla.co​m/photo/strobeVolts.ht​ml

Q2: Hooking up 3 flashes (hypothetical)