for just a minimal/basic grow you need the two biggies: nutrients and light
you can easily get a quart of Pure Blend Pro Grow/Bloom for around $30.
As with lights, the more you initially invest in good lights, the bigger payout in the future. Good lights=bigger yield. My experience with a 400w mh/hps system for 2 plants yielded almost 4oz. (The light cost around $200 for the whole system: hps and mh bulb, ballast, reflector)
best strain to grow? they're all good. if you're asking which is easiest to grow, go with a indica-dominant strain. they are usually more forgiving.