>>2638783are you specifically wanting WET plate? i haven't looked into it too much but dry plates give a very similar effect but are:
1. faster (~iso 6-10 instead of ~iso 0.5-1)
2. less explosive (gelatin based instead of collodion/ether based)
3. less deadly. (for some reason people like the cyanide fixers instead of the sodium thiosulfate ones)
rockland make a tintype DRY plate kit which im yet to try (i have an 8x10 kit sitting in the corner) but if you specifically have your heart set on wet plates, bostick & sullivan are known to be the #1 supplier for this. it also depends which country you're in
you can buy a LF/wet plate camera, but i'd do it only if you get a good deal. personally im cutting up my plates to fit into used fp-100c cartridges so i can wedge them into my old Polaroid 103 & RZ67. i figure shoot more tiny ones before i burn up an 8x10 plate or invest stupid amounts of cash in an LF camera