The only optimal charge for NiMh batts is some kind of peak detecting charge where the charger senses the small characteristic rise in voltage as the cells become fully charged. You can't match this with a wall type charger no matter how long you allow it to charge.

The 2/3a cells that are used in rx packs don't like charging at more than 1amp and life and performance will suffer charging at more than 1amp. I charge mine 1400s and 1600mah rx pacs at 0.5amp and only charge at 1amp when I'm pinched for time.

This is a decent, cheap charger and can balance charge lipo when you get there -

http://www.hobbypartz.com/thac6smbachw.html

NiMh are supposed to be stoed charged and cycled one a month to best maintain them. You will need to cycle them until you see the disch mah stabilize. Would be best to start with what is known as a forming charge - a low rate, very long charge to wake them up, something like 16hrs at 160ma. Then cycle them and see what kind of disch numbers the pacs puts up. If I don't run mine every month, it takes 2 or 3 cycles to get them back cycling them at 0.5a disch, 0.5a charge.