You may consider increasing bandwith of your filter to 6.5MHz. Also, I would use matching buffer/amplifier befor LPF and matching buffer/driver after.
By doing this you will be able to adjust the auptut level back to 1Vpp@75Ω.
Passive components such as ceramic capacitors and RF inductors can be used in your filter. Make sure that self-resonance frequency for inductors is above 8+MHz.
Other alternative is to use active filters based on video amplifiers (special type of op-amps). Cascading them will give you sharper atteniuation and the video level within the banwidth will be maitened.