Hi and welcome to Armorama.
Sorry I cant give you any advice on bases.
I use an airbrush for all my camo schemes and the best advice I can give you is to mask carefully and spray in light coats.There are various methods for masking depending on what particular style of camoflage your doing.
Dont be afraid to experiment,and if it all goes wrong you can easily fix this by stripping the paint off with oven cleaner,(which I learnt from this site).It doesnt harm the plastic.
You'll have lots of fun on here and find everyone very friendly,helpfull and informative.Dont be afraid to ask what may seem the dumbest novice questions ever.You will always get helpfull answers.
Ive only recently come back to the hobby and Im learning all the time.
Looking forward to seeing your work.
Feel free to post "in progress" pics and if you get stuck on anything at all you will find the answers on here.
Happy Modelling!!