Addon's you will have to find yourself, some older versions can be downloaded through places like curseforge and wowinterface but some you will have to take them where you find them (google search).
I have posted a webby link in a forum post for 2.4.3 addons and ive tested them on a current open TBC realm and the ones I have used seem to work fine. I found curse wasnt having all versions of addons mainly starting from WoTLK and up :)
I also used the link from warmanes site for the client download. Not sure what you mean by trusting :) I used uTorrent to DL it. got it in 1hr 30 there abouts just have to set bandwith priority and away you go :)