The best place to get more piggies and make sure that they get on is one of our recommended rescues, so you run as little risk of things not working out as possible, especially as you are not yet experienced to read all the subtle body language and behaviours that are crucial when bonding.
The dedicated rescues we are recommending are all volunteer run in their free time, so please be patient. Rescue people are VERY busy people and the welfare of the animals in their care has to come first. If you haven't got an answer in a few days, try again. I would also recommend to contact all rescues within your reach if there is more then one.
As to bonding tips, see our various guides at the top of our behaviour and bonding section.