Does readily available hardware exist which is capable of at least 25MH/s for litecoin mining?
So basically, I am after hardware which can mine scrypt type coins which can do at least 25MH/s.
Here is a quite detailed Litecoin mining performance collection for different hardwares.
You could put 6 of them in 1 machine.... Totalling about 9Mhz ... So you would need 3 of such machines. Warning though, putting more than 2 amd 7990 cards in a machine will give you heat dissipation problems
The list that Tibor identified is old school, contrast it this emerging FPGA/ASIC list for Litecoin.