The LT-6401-20 looks like a good choice to me for a pre ADC amp here. It is specifically designed for this purpose and is capable of a 6.2 dB NF up to 100 MHz and a +55 dBm OIP3 at 30 MHz.
I am looking forward to receiving the RX-888 and try it out with SDRC
Does the RX-888 need any different drivers than the RX-666 in order to work with SDRC?
73 / Ingolf, SM6FHZ