Hi go for GOS (then I am a GOS addict
). If you are intending to sell the meat, and from 6 pigs thats a lot of meat, as JulieS says make sure you have a market. Also make sure your costs will be covered, and that you are abiding by all the rules re sales of pork.
Once you have done so, then consider that you need to add value to your meat, perhaps in the form of sausages, ham, gammon and pate. Utilise everything including head and trotters. Anything you throw away is a potential lost income.
If you are new to pigs then please consider waiting a while to breed. Firstly you will need a good market for the offspring, secondly you will need experience to deal with the sow. Some can be very nasty when you try to take the babies off them. Even the gentlest sow can and probably will become very protective of her young.
Try to go on a good pig keeping course, specifically one aimed at breeding so that you will be aware of the pitfalls and the dangers. Money spent now could save you much more at a later date.
Above all I would strongly recommend you take deposits on any sales before the pigs go to slaughter.
Having said all this, enjoy your pigs, they are the most wonderful of animals.