try doogle and procorns (adsclark and Vetdebbie) al members on here, you will be able to get quality corns from these folks and yuo could arrange courier is better than chancing it with the online shops.
do CPR do delivery? i think 888 do........ i've not used any online suppliers for livestock, though you tend to hear any horror stories about places more than you hear praise and i've not heard anything bad about either of the 2 above
but as G said above, are there any reputable breeders near you? where abouts are you?
cornsnakes, ratsnakes, bullsnakes, boas and day geckos