800g...?
how many are you planning to have...? unless you have a huge quad vortex chamber filtration system, you shouldn't have more than 4-5 koi fish....
if i were you, i would invest in two pairs of premium koi... i used to get them from a breeder in SGV... 150 per 16" japanese koi... or 200 for a real import... there is a huge difference in japanese koi... some will breed true... the american farm raised koi don't always keep their color... i had some chagoi that turned into ogons after a year... wack...
but if you just want whatever koi, hit up ebay or craigslist... the season is almost over for outdoor acclimation though... you better hurry up and get them like, now...