Hey man, hope I can help because I was shooting for the same options you're looking for. I should mention that I use the Sennheiser HD600's (300 Ohm)
Unfortunately I cannot comment on the Bravo or the E9 because I don't own them. However, I do own other amps that I've directly compared to those 2 and I think you'll be happier with these options.
I purchased a Schiit Magni Headphone amp ($99) and it's AMAZING!! I would HIGHLY recommend this if you're looking for a POWERFUL yet inexpensive headphone amp that is ready for most high-end cans. It very powerful, and looks stunning. I'm not lying when I say it's worth 2 - 3 times the cost their asking. And it's 100% American made. (just assuming you live in the US
)
http://schiit.com/cart/index.php?main_page=product_info&cPath=0&products_id=13
I also own the HiFiMAN EF2A which is a Tube/DAC Hybrid which retails for $169. I use both equally for different applications. Music with the EF2A and Games and Movies with the Magni. The EF2A with aftermarket tubes sounds warm and vibrant and has plenty of oomph. Plus the addition of a nice Burr Brown DAC is nice. A neat little amp that looks nice as well!
http://www.amazon.com/Hi-Fi-Man-EF2A-Tube-Headphone/dp/B004357WL8/ref=sr_1_1?s=electronics&ie=UTF8&qid=1368131117&sr=1-1&keywords=ef2A
I hope I didn't make this a whole lot harder for you
I just didn't want to leave you hanging when this forum has helped me on so many occasions. These little amps sound MUCH better than straight from my Onkyo TX-NR609 AV Receiver. They are very impressive indeed.