I would not suggest you have more males then females. The males would still try to mate with the females, and therefore would continue to stress them out. Especially since the males will have no females of their own. Maybe 3 and 2, if you have to have more males then females, but I would not go above that. Especially with your sized tank, and I'd definitely recommend you have a LOT of hiding places.
Thanks, i asked on irc and they said that its possible as theyre different spiecies and the male guppies wont be so interested in the platies, there may be some aggression. What do you think?
I would recomend that rather than postulale back and fourth you try it, and if your male gupps are to "frisky" then you can split them up and possibly take some of them back.