It’s possible to have SIBO and a candida overgrowth, and not that unlikely since imbalance at the beginning of the GI tract doesn’t exactly support a healthy colon. I’d assume it’s a problem as long as yeast infections occur.
You have to adapt your approach slightly to target either bacteria or yeast, and it makes sense to get things in order in the stomach and small intestines first. A low-fibre ketogenic diet with plenty of coconut oil will probably keep candida in check until you can focus on it fully.
It’s important to remember that your body doesn’t fit neat diagnostic labels like SIBO and you could have a number of issues – hormonal, psychological, metabolic, immunological, nutritional etc – that need addressing. It’s not about ‘I have condition X’, it’s about doing everything you can to restore your health, which seems to take a lot of research, trial and error and determination. In some ways getting a label like IBS is a big setback, at least it was for me with “RSI”.
My Japanese friend (in Japan) gets good shipping rates on iHerb (US site). Have you checked on there for supplements? For biofilms, I think it’s best to take a short, focused approach because it’ll disrupt everything, good and bad. Waiting until you feel you’ve improved somewhat and know exactly what to do isn’t a bad idea. The more good bacteria you have in advance, the better chance they have of rebuilding strong after the disruption. I can’t really tell you more than what’s in the thread, but hopefully you can read the protocols and come to your own conclusions. Good luck!