The headroom bithead is a possible suggestion, but the only low cost commercial headamp I'd recommend would be the Rega Ear. The Creek has a high output impedance which will muddy the sound (much like integrated amps headphone sockets, so dont even bother with a creek if you have an amp with a headphone socket), the Project is not highly rated at headfi, and the X-Can is a mediocre amp which has an expensive habit of using valves rather quickly. It can be made to sound good with mods, but for the price, you may as well buy a better amp to start with.
Alternatively, PM someone like JMT at headfi.org to get him to make you a PIMETA.