Stem plants are usually pretty cheap, 4-5 dollars worth of Anacharis, hornwort, and/or hygro really ought to be enough. thats 5 bucks total, not of each type. They will suck up ammonia so fast you won't believe it. If you just have some stem plants, and more rooted varieties, just stock your fish slower and you/they'll be fine.
I get frustrated when I read posts like these on a day like today, when I threw a couple pounds of hornwort and anacharis on the compost heap. Wish I could help, but shipping costs aren't worth it, dang it!