Baking soda as leavening agent only works in connection with an acid, such as citric acid from lime juice or lactic acid from yoghurt. A certain ratio of baking soda to acid must be met for best results.

Baking powder is sort of of an Instant Baking soda because it's a combination of baking soda and cream of tartar, which is basically wine acid. Plus, maybe some preservatives sometimes.

The yeast you have is a dry yeast. It might be Active Dry Yeast or Instant Dry Yeast, I don't know what's more common in the UK. Over here the powdered stuff is Active Dry Yeast. For most intents it doesn't make any difference (there's a negligable amount of difference in the way they should be dosaged but it really only applies to very sensitive doughs). There's also fresh yeast (aka cake yeast) which I often use for baking. There's also champagne yeast, ale yeast and so on but the latter are only available in specialty shops.

The reason why some recipes call for a combination of baking soda or baking powder *and* (fresh or dry 'baking') yeast might be because both react at different times and/or temperatures. Some recipes even include baking soda and baking powder, which seems a little redundant, but maybe there's a lot of acid in the dough.

To answer your question - yes, both seem fine to me

thanks for the lengthy information StoneCut!