I am wanting to order a new HB 898 and just wanted to make sure it does down Imaging and side scan. Some descriptions say side scan and dual beam sonar. Thanks in advance for any info on this. Also, when ordering do i need to order anything else besides the unit/with transducer and puck. Ram mount and I was going to order transom mount piece to avoid putting excess holes in transom in case it was not mounted correct the first time.