The Seven Suitables are conditions, which the Buddha said if all these seven are present you are going to have a very good practice, things are going to be very comfortable, you are going to have conditions conducive to wisdom growth. So, there is suitable food, suitable climate, suitable home, suitable environment outside of home (which includes your work place and your "play" place), suitable posture, suitable friends, and suitable conversation.
Now when you look at these seven, two are very distinctly different to the other five, suitable friends and suitable conversation. They normally go together, right? What we are really talking about with suitable friends is Kalyanamittas, good wise spiritual friends,. Whether it is a teacher or another practitioner who is working hard in the Dhamma. These two are special. Food, home, climate, whatever, they are more of a physical environment type condition. To give you an example of how it applies, if I am in Canada, I live in Alberta where it snows half the year or more, it is not a suitable climate for me. If I live, say in Italy, and I am given spaghetti and lasagna everyday, everyday (not that they eat that everyday), it would not be suitable food for me. So, you can know for yourself some of those suitable conditions. Yet as much as all seven, if they are all suitable, would be the best conditions we could have, it is possible to have those first 5 not so suitable if the last two are suitable.
If I have a wonderful teacher and I have Dhamma talks everyday with this teacher, I will eat lasagna everyday, I will live in Alberta. So that is where those first 5 would be nice, and we would like to have them, but the last two are the most important.