Just grab some sorty of outboard processor with line gain.. 10 years ago i had an RME converter and would go out two of the A/Ds and into my Roll Music 755 comp (the first one made!) and then i'd drive the output gain and clip in the input of the RME to get loudness. It worked fine and despite the fact that it doesn't say Lavry or Prism on it, it works. I'd bet your RME would clip fine despite what some have said here. Clipping is still a very popular method of many pro mastering engineers and many rock records that you've listened to over the years have acheived their loudness this way. But after -10RMS, it severely alters the sound of the low end due to fullscale shape.. So you always have to EQ into it to fix what it screws up. Broader curves (sometimes very broad shaped curves) work better for low end. This is why the FG-X changes the shape of the curve according to what type of frequencies dominate the transient. So find some outboard with a line output gain and try it out. Its still about 1000 times better than any brickwall peak limiter if we're talking about most rock and pop music. It would be good to experiment.