for the transparant background, if you want to be easy, use ROSpr toolkit. you can downlaod it from ratemyserver.net
if you already create the item image, make it into indexed colour on Image > Mode > Indexed Colour > OK (Photoshop)
after that open your ROSpr tool kit, btw the background image must be the same like the other frame also..
then convert image to spr
the program got language error i guess, so choose Image -> Spr then press "??(A)" Button, then add your image.. after that press "??M" then choose where you want to put the spr files, dont forget to put the ".spr" on your sprite file name ex : test.spr
hope you understand what i tell, coz my english also bad XD