I see CEAFAR and SPY1 as complimentary.
SPY1 is going to be in the US mix (and the JSDF, and SK and Spains, etc) for a long time. It is also quite capable.
Money time and energy would be better spent else where, replacing far less capable systems with far better systems.
SPY-6(v) would be the SPY1 replacement, which is meant to be 30 times more powerful. However, I doubt that they will try and cram that into an existing F-105 hull. Power, weight, volume, thermals would be a nightmare.
20 years (30+ if you think about the F-105 design) is a long time in Radars.
IMO you want a nice big wide ship so you can fit a nice big radar, up high.