Recently purchased a used 420ex for my xti . 420ex has built in wireless slave receiiver but my xti has no built in transmitter. Im browsing in ebay at he moment for some cheap on the budget wireless trigger kits. I was thingking of either the ishiloot pt-04 or tue yongnuo . Anyone know of any cheep transmitter the would work with the built in 420ex receiver with out have to clip on additional recriver on the flash . Thanks in advance hope thisvmade sense.