For trainers I've heard good things about these but no personal experience:
http://www.snap-ez.com/CottonTrainers.html
(come in regular and AIO)
Also, Country Cozys sells the pattern for their Knit Knickers. Or did sell the pattern. The site closed down a year or two ago, and I can't remember the mama here (and at md) that owned it.

Anyhow, the pattern is worthwhile if you can find it.
I DON'T recommend Happy Heinys pocket trainers. They're made fine and have great fabrics and fit bigger kids, but a PITB to put the stuffing in!