I'd say you're way to close to your products here and need to start asking your customers. For example, the stoves in the picture - to me - are all the same stove.
I have the same problem with dental products. Are 'All on Four Implant retained Dentures' the same 'topic' in the eyes of google as 'Dental Implants' and then are they going to internally compete with my dentures and Implants pages? It can be a nightmare and the way around it is with testing and also taking a more global view of things and taking a step back from the technicalities.
People don't want a 'black trim 85/1 wood burner. They want to feel warm and have a beautiful addition to their home that makes them feel aspirational or romantic or happy. This is what you sell. Not technical specifications. People want simplicity not complexity and they want benefits not features. So bundle it all up into one page with some really evocative and emotionally charged sales copy about how having a stove like this is going to change their hoes and make their lives better.
From a technical perspective there's going to be a hopeless amount of internal competition that's going to be depressing your rankings like crazy. So experiment with bringing the pages all together and having variations available on page.
I got some headphones the other day and there were about a hundred variations of colour, size, type of ear bud and it was all just available to me with dropdown menus that brought up an image of what i'd chosen. People don't want to have to navigate around from page to page to page to find what they want. They want to get the general picture and then decide on the specifications later. If I listed everything we did at our dental practice do you think that would make patients want to buy?
How about a root canal with a .0012/in burr and chlorhexadine irrigation? High-speed or low-speed handpiece? Would you like a rubber-dam with that or take your chances with a file in the windpipe?? Perhaps you'd like me to irrigate with hypochlorite instead?
OK i'm being silly but this is actually kind of like what you're doing here.
Keep it simple. Merge the pages together and watch your rankings creep up for all your high traffic high purchase intent keywords. This (as you say) helps with links and also helps users stay on one page for longer and it's this implicit user feedback like time on site, scroll depth and bounce rate that google is looking at.
When customers get lost and bounce this also MASSIVELY depresses your results. i see it with my visitor recording software. and it's a very strongly correlating ranking factor.
I'm not ecommerce but i've had HUGE success figuring out which topics google considers to be topics and which are separate and the only way you can find this out is with testing it. For words and search terms it's easy. If you type in "wood burner cost" and "wood fireplace price" comes up in bold in someone's meta description then google considers them to be the same. So price is the same as cost etc. Sometimes that can be a good place to start. Also do a search using site:www.yoursite.com wood burner and see how many pages come up. If it's hundreds then you've got internal competition problems. Use more and more granular searches like this to determine if you're getting stacking or competition or even cannibalisation in the SERPS (which is getting filtered altogether)
Hope this helps!