I wouldn't personally recommend them for practice, no. Only because most don't feel like really guns, don't have all the safety features, and the rounds fly everywhere in every direction once they reach a certain distance from the barrel. (Depending on the weight of the BB) The .25 gram ones are okay.
Personally for training I really like the Walther PPK/s air pistol. Its inexpensive, feels like a real pistol, has a nice realistic blowback feature that is a big plus for training, and has all the safety features of a real pistol. NRA uses these for youth pistol training I believe. C02 powered, has a decent BB shot capacity in easily reloadable magazines...its sweet.
Here's a nice little kit http://www.pyramydair.com/p/walther-ppk ... -gun.shtml
--- otherwise you can buy pistol only: http://www.pyramydair.com/p/walther-ppk-bb-gun.shtml
I recommend pyramid air they're a good place to buy from. Anyway, the accuracy won't be as good as say a pellet pistol, but its better than an airsoft gun.