If you aren't using Psiconics, then, yes, bottom line you will lose something. Your question is what to replace it with?
Some possibilities:
* Sorcerer levels (with chosen spells that mimic your psiconic abilities as best as you can)
* magic items that mimic what you could once do
* chosen of type template that you mentioned (there is some magistar template in Magic of Faerun -- I don't recall the specifics but it was something like the chosen of a magic diety)
* retire the character -- there is no way he will be the EXACT same because of the change in editions and because of the lose of psionics.
some others that have already been mentioned are good too.
(i'll add to this list if i think of more later -- I've been up all night and need some sleep
)
Some possibilities:
* Sorcerer levels (with chosen spells that mimic your psiconic abilities as best as you can)
* magic items that mimic what you could once do
* chosen of type template that you mentioned (there is some magistar template in Magic of Faerun -- I don't recall the specifics but it was something like the chosen of a magic diety)
* retire the character -- there is no way he will be the EXACT same because of the change in editions and because of the lose of psionics.
some others that have already been mentioned are good too.
(i'll add to this list if i think of more later -- I've been up all night and need some sleep