Repitbark or perlite are definitely options, although the more expensive options as compared to pine bark. the pine bark mulch doesn't have to be composted. Mine isn't. Just hate to see you spend a fortune.

I have had good experience with some bagged soils. Look at the ingredients for those you most like. I have a set of screens from 1mm to 9mm in 1mm increments. Just screening some soils for the upper and lower particle sizes needed helped. The quality soils can be expensive like Pro Mix HP and Sunshine #4 Aggregrate about $24 per bag. I have tried StaGreen from Lowes, it was ok for the annuals. It was a good price, but has CRF added. I just screened the fines <1mm or 2mm, added some perlite or pumice. Add 10 to 15% Calcined Clay if wanted. It is better to start with a very small quantity of soil to evaluate, before planting up everything or commiting to one.

Also Purchasing a Large Bales of Sphagnum PeatMoss, Vermiculite, Calcined Clay, and Perlite or Pumice. Mixing up a batch of custom Mix. But note, not all Peat moss is equal. Some is over milled, or just left over fines (MG etc). Get a good Quality Coarse Sphagnum PeatMoss, Sunshine or Premier ( maker of Pro Mix). Screen it if you want, use the fines around the yard. ProMix is just Sphagnum Peat: Perlite (2:1) with Dolomite ,Gypsum, and Mycorrhizae added.

My personal preference is to avoid bagged peat or coir based soils altogether and go with an adjusted rendition of the Gritty or 511 Mixes, as described in Al's article on "Container Soils - Water Movement & Retention".

I find that a more porous medium actually gives my plants' roots the proper environment to grow and remain healthy in, without perched water sitting anywhere, or soggy rootballs while the surface seems dry. The mediums i use are free-draining and give the plants what they need without remaining soggy for too long a period of time.

Link - Container Soils Article

It's definitely worth a read to find out what purposes plant roots serve, what actually happens under the soil surface, and to gain a little knowledge on the basic physics of how water moves through various materials within a confined space... and that's precisely what growing in a pot environment is... it's a confined space.

Pots don't have the same army of living things that gardens do, continuously moving and aerating the soil, or the ability to avoid perched water tables. So, we have to control the elements that make up our potted plantings and keep them growing in a healthy manner.

It's not the actual mix recipes that are important... it's an understanding of the concepts discussed in the article that are important. Once you understand the concept, you can adjust the ingredients you use, the ratios, etc... and make it fit your own individual growing environment... which will naturally differ from anyone else's.

Happy Growing!