A lot of youtubers take money to promote a product without disclosing. You are creating content for people to watch. You should be able to take advertising/promotion money. Its a business. If people don't like it, they can watch something else.
Sure, you are doing this out of passion but (as you mentioned), you are also doing it for an income stream. That's great. Appreciate the transparency that you will disclose when it is a paid review.