You won't believe this but try Wal-Mart! The super center here in Clanton have onion sets, seed potatoes (several kinds!), asparagus even! Those peas hmm, I'm not real sold on. I find if I don't sow them back in Jan/Feb, the heat saps 'em before I get enough for a stir fry! Also remember, since we are still experiencing some very cold nights, some of the more tender plants you may set out would benefit from a garden "blanket" (row cover) to prevent frost damage

Hardware stores are the "traditional" places to purchase vegatables for your garden. You may have some luck there.

I found some but now it's raining. I hope I can get them in the ground before it's to late.

Dude your ok on the potatoes. I planted mine last year in late march/early April and they did fine. You look like you have great soil for potatoes. Just remember as they mature(get taller)keep piling the soil around them. They more you put to them the more room they have to make spuds.
I am actually growing my potatoes this year in nothing but chopped leaves and grass clippings. Should be interesting.

Here is a link that might be useful: Dannys Vegetable Garden

I just planted the potatoes yesterday. I'll try to post with updates on those.