Hi - I do wetplate and am in the UK. You can get materials from www.sigmaaldrich.com/ but: you will need to apply to customs and excise to get a permit for the 190 proof alcohol you will need. flexible collodion will not work - it has an oil incorporated into it to keep it - you guessed! - flexible. I think that the collodion used to clean telescopes/lenses with is the flexible sort.

You will need much more than just collodion: ether/alcohol/chloroform/silver nitrate/rottenstone/cadmium bromide and-or iodide/potassium bromide and-or iodide/ammonium bromide and-or iodide/ferrous sulphate/acetic /glass plates/glass cutter/glass grinder or file/tin sheets/asphaltum/acid/sandarac/lavender oil/tincture of iodine/potassium cyanide or hypo.

Some things can be substituted for with others, some you can do without, some won't be needed at all if you do certain types of wetplate exclusively.

It would be best to get a manual first - John Coffer does a good one.

Good luck,
Neil.