Retrofit 4 Godin Rounds Chimney Liner Questions

Hi Everyone - I've been carefully reading a lot of the posts on this excellent web site, as they pertain to our particular situation. We are attempting to retrofit 4 Godin rounds into our 1793 early Federal home in western New Hampshire. I've been busy acquiring the Godins for a while, and have gotten some great deals, on some near new stoves. We have a newer center chimney with a 12" X 12" fireplace flue and separate flues for the oil boiler and a former wood stove flue (I believe). I had the chimney partially rebuilt in 2004. There are clay liners in it. We plan to use a double-wall through the wall chimney for our kitchen. That appears pretty straight forward.

My question is, has anyone used Magna-Flex or Flex King stainless 316Ti liners, both of which are offered on eBay for excellent prices. The pricing of these kits confuses me, as the quotes I've been getting for liners (not including labor) from chimney liner installers are A LOT more money. Are these products junk? An installer I just spoke with in Vermont said he'd install my kits, but was concerned about the quality and warranty.

On a related issue - Inventex.com in Montreal does have a lot of parts for these stoves, but their web site is only partially working, so an email with what's needed would work better. They said they would answer with diagrams and pricing.

Looking forward to beating the high cost of oil with coal - a USA product!!!

Any help on this would be appreciated - Chris