Meccano advice

[supersigningmum]

Was thinking of buying some Meccano for DS aged 4 but not sure whether to go for the "kids play" models which say they are for age 2+ or the "build and play" range which are for age 4+. He is not daft but in my experience with other construction things (namely Lego) he gets v frustrated when he can't do it on his own. Anyone got any advice?

Ta!

ds1 (just 5) had some build and play mecanno for xmas when he was 3y3m (am pretty sure it was then and not 4y3m), he couldn't do it at all. He now plays and makes things with Lego and K'nex, but can't make up the mecanno into proper things - usually makes guns!