Either fabric would be great as a business suit, unless you're FNB. If you do want it as a suit, there are a couple advantages to getting it made that way off the bat: it's a bit cheaper to order a suit than a coat and jacket separately and sometimes fabric rolls vary in color so it's ideal to cut a suit from the same roll and even the same area of a roll.
The finmeresco is 11.5 oz, I think, which is a solid weight for a suit. It's 4ply, which makes it very wrinkle-resistant and durable. But the open weave makes it wear cooler than plain weaves or twills of similar weight. So you'd need to consider weave as well as weight.
By "quarter lined" Chan means something different from what apropos meant above. It will have more lining than my coat, also above. I think there are pictures of quarter lined Chan coats on SF, but Patrick can show you what they are. They're really about 40% lined. I don't know if you saw my blazersuit thread
, but it may be helpful to you.