I've been taking photos for a while, but mostly nature and abstract. I've been asked to take several portraits lately and I must say, I'm beginning to enjoy it. Right now, I have a D300 and an SB 600 which I can command off the D300, but I need more light. I'm not up to spending a tremendous amount of money on a full lighting set-up right now, especially because I'm very new to it, but, I'm trying to decide if I should get a small strobe kit, constant kit, or two more SB 600s and a few umbrellas and reflectors. Whatever I get has to be mobile because I live in the sticks and have to travel with all my gear. Opinions please.