The purpose behind 5 sources of compost is for nutrients, not the media's water holding, drainage or workability qualities.

There is no magic in the number 5. It is what Mel recommends so one can grow without the use of fertilizers.

If you have access to a single source of compost that was made from a diversity of ingredients and not enclosed in a plastic bag it will be fine.

If you intend to use fertilizer (synthetic or organic based) you can skip the 5 sources altogether.

Something else to consider is that compost isn't stable. Your growing mix volume with shrink over time as the compost breaks down. This means you can incorporate additional sources of compost over time to replace the lost volume.

Your leaf source is fine if they are mostly broken down. If not you can use them as a winter mulch and dig them in come spring or you can grab them up now and put them in plastic trash bags and leave them sit a year. They will become leaf mold which is quite valuable as a soil amendment.

I seriously agree with justaguy2 about the leaves, grab them now! even if you just have to save them.

It's the ultimate in garden nutrients.