Thanks for the response Frank - It's good to know you were in the same situation and what you decided on is working for you. Good point about ranking multiple pages too, that would make us seem more authoritative if that happened.
Leaning a little more towards the blog posts

Hi,

We have around 40 products which we can produce plenty of in-depth and detailed "how to"-type pieces of content for. Our current plan is to produce a "How to make" style post for each as a long blog post, then link that to the product page. There's probably half a dozen or more of these kind of blog posts that we could do for each product.

The reason why we planned on doing it like this is that it would give us plenty of extra pages (blog posts) on their own URL which can be indexed and rank for long tail keywords, but also that we can mention these posts in our newsletter. It'd give people a new page full of specific content that they can read instead of us having to say "Hey! We've updated our product page for X!", which seems a little pointless.

Most of the products we sell don't get very many searches themselves; Most get a couple dozen and the odd few get 100-300 each, while one gets more than 2,000 per month. The products don't get many searches as it's a relatively unknown niche when it comes to details, but searches for the "categories" these products are in are very well known (Some broad terms that cover the niche get more than 30,000+ searches a month in the UK and 100,000+ world wide) [Exact].
Regarding the one product with more than 2,000 searches; This keyword is both the name of  the product and also a name for the category page. Many of our competitors have just one of these products, whereas we're one of the first to have more than 6 variations of this product, thus the category page is acting like our other product pages and the information you would usually find on our product pages, is on the category page for just this product.

I'm still leaning towards creating each piece of content as it's own blog post which links to the product pages, while the product pages link to the relevant blog posts, but i'm starting to think that it may be be better to put all the content on the product pages themselves). The only problem with this is that it cuts out on more than 200 very indepth and long blog posts (which due to the amount of content, videos and potentially dozens of high resolution images may slow down the loading of the product pages).

From what I can see, here are the pros and cons:

Pro (For blog posts):
1. More than 200 blog posts (potentially 1000+ words each with dozens of photos and potentially a video)..
2. More pages to crawl, index and rank..
3. More pages to post on social media..
4. Able to comment about the posts in the newsletter - Sounds more unique than "We've just updated this product page"..
5. Commenting is available on blog posts, whereas it is not on product pages..
6. So much information could slow down the loading of product pages significantly..
7. Some products are very similar (ie, the same product but "better quality" - Difficult to explain without giving the niche away, which i'd prefer not to do ATM) and this would mean the same content isn't on multiple pages.
8. By my understanding, this would be better for Google Authorship/Publishership..

Con (Against blog posts. For extended product pages):
1. Customers have all information in one place and don't have to click on a "Related Blog posts" tab..
2. More content means better ability to rank for product related keywords (All but a few receive very few searches per month, but the niche is exploding at an amazing rate at the moment)..
3. Very little chance of a blog post out-ranking the related product page for keywords..

I've run out of ideas for the 'Con' side of things, but that's why I'd like opinions from someone here if possible. I'd really appreciate any and all input, Thanks!

[EDIT]:
I should add that there will be a small "How to make" style section on product pages anyway, which covers the most common step by step instructions. In the content we planned for blog posts, we'd explore the regular method in greater detail and several other methods in good detail. Our products can be "made" in several different ways which each result in a unique end result (some people may prefer it one way than another, so we want to cover every possible method), effectively meaning that there's an almost unlimited amount of content we could write.
In fact, you could probably think of the blog posts as more of "an ultimate guide to X" instead of simply "How to X"...