If you crunch the numbers, it turns out the bad news is a Bussard ramjet won't work as an engine. The good news is, it will work as a brake. That takes care of

If you crunch the numbers, it turns out the bad news is a Bussard ramjet won't work as an engine. The good news is, it will work as a brake. That takes care of the deceleration half of your delta-V requirement, which is better news than it sounds: thanks to the rocket equation, it doesn't just halve your required mass fraction of fuel, it square-roots it.