Component/design recommendations for high power RF switch IC for 1-50 MHz
PIN diodes with suitable biasing arrangements? 

The low frequency end may be the difficult one to source here as it needs diodes with very long carrier lifetimes (at least several microseconds at 1MHz), MACOM have suitable parts. 

Not a cheap option, and I would note that if this is for something like LPF switching then relays can be highly reliable as they should never have occasion to switch under load, and mechanical latching ones will reduce your idle power requirements, relays are also pretty much imune to static discharge which cannot be said of PIN switches.

Have a look at the circuit for that MFJ QSK board for ideas. 

73