Interesting, but you didn't answer my questions. Do you have a PLL that will run on 5V at 300+MHz, or are you after some other logic level? I'm not just asking out of curiosity. Knowing the details of your application can help us give you useful answers.
Note that the gain of the CLC449 is down about 8dB at 300MHz, which means that you'll have a net gain of 12dB, which is a gain of 4 (not including the loss of your "voltage follower"). Not too effective. Furthermore, the peak output voltage is only 3.1V. Also, the slew rate is 2000V/usec. This means you can only get 2V p-p output at 319MHz. You plan to clip the negative portion. Is 1V peak enough?
for a sine wave, max dv/dt=Aw, where w=2*pi*f, A=peak sine wave voltage
A=(dv/dt)/w
A=2e9/(2*pi*319e6)
A~1
A sine wave should be fine to apply to a PLL, even a digital one, at 319MHz. You just need the correct gain and DC offset (with AC coupling), and maybe some Schottky limiters for protection if your source amplitude is variable. I would not try to get that gain with op amps.