If you have your DM fix the Metamind PrC, that is an option, especially for an Egoist who likes to change himself and fight in melee. My suggestion for Metamind is to add "+1 level of existing manifesting class" back in for all levels expect level one.
That means that a:
Psion 15 with Int 20 has 8th level powers and 232 PP
Psion 5 / Metamind 10 with Int 20 has 7th level powers and max (with crystals) 249 PP plus 140 extra max PP (without feats) for one minute per day
as opposed to the core rules of:
Psion 5 / Metamind 10 with Int 20 has 5th level powers and max (with crystals) 157 PP plus 100 extra max PP (without feats) for one minute per day
As written, the Metamind is never worth taking since he has fewer PP (and fewer powers) than a regular Psion except at Metamind 10 where he could actually manifest about 25 extra PP in a day.

This is not worth 5 manifesting levels.
With this adjustment, he is a worthwhile PrC since he gives up a single manifesting level in order to eventually have PP to burn. Although his PP is actually slightly lower at Psion 5 / Metamind 1, he actually catches up with this house rule by Psion 5 / Metamind 5 and Font of Power really gives him the PP edge at Metamind 10.