dovetailing

Got a small dovetail fixture for Christmas that does 1/2" and 1/4" dovetails. Does it matter what the angle is? The instructions give a part # for the 1/4" dovetail bit but at the store the salesman gets mistified and starts speaking in tongues and wants to sell me a 1/4" straight bit. I need a...

With an ominjig 7116, can one join (with a 1/2 blind joint) a 3/4" drawer front to 1/2" drawer sides? I'm new to all this and have not used a router very much, Any help is appreciated! Thanks