Yup, definitely go for wooden rings if you can. They are much nicer to use than plastic rings or the TRX handles. Plastic rings get all sweaty and slippery and the handles only really have one holding position.
Pullup and dip have a new style of hybrid rings in their new kickstarter which I am interested to try. They have both a rounded ring side and a flatter handle side. You can see them on the campaign images - doesn't look like they sell them separately yet.
https://www.kickstarter.com/projects/pullupanddip/freesixd-w...
Pullup and dip have a new style of hybrid rings in their new kickstarter which I am interested to try. They have both a rounded ring side and a flatter handle side. You can see them on the campaign images - doesn't look like they sell them separately yet. https://www.kickstarter.com/projects/pullupanddip/freesixd-w...