Need Help

[jeffnae]

My Fiancee has taking a liking to the Gold spot Pleco or a "firefin" i could be wrong with that..

I am just wondering whether anyone can give me any advice about mixing plecos..
Currently i have a Clown pleco 12cms or so.. and a Sailfin pleco only had him a few weeks and is around 5 cm i would say..

I also like them But from what i have read a good time to get one will be now so they can grow up together...
Is this correct or not..
Atm i have a 5ft tank if that helps..

Thanks
Renae