I am finally looking to get side imaging. I have two boats so looking to swap whatever i get between the two. For that reason i want internal gps to save buying one. I believe the 998 is external but the 999 and 1198 are internal. If i buy one of those what would i need to buy as far as transducers for second boat. I know i would need power cable. and is it possible to get rid of white readouts on 999 on all screens yet