done both and i would recomend either of them, if its your first course you'll be put off a bit because theres a lot more to take in than you could ever think. i did prochem 2 day first and nearly came home after the first day, stuck it out and it started making sense on the second day, then i did the ncca 2 day and the light bulb came on. simples.
so to some up, do both if you can afford it, but if not either will suffice, there both excellent courses and paul pierce at the ncca is an excellent teacher, and a bladdy nice bloke.