Dark suit/Odd jacket?

[SMCK]

I live and work in the country.
I always wear a jacket,but find that as times change I have increasingly little reason to wear a suit.
My tweed suits hang unworn next to a very rarely used morning coat.
There are occasions when I find that a suit is useful:Weddings where morning coat is not required, and funerals.
On this basis ,I am thinking of a new dark suit for these occasions, the coat of which could double as an odd jacket.
Not wishing to look like a banker or office worker, I have dismissed pinstripes.
I am thinking that a dark navy SB or DB peaked lapel could double as a blazer.
But as I consider metal buttons a bit 'flash', a blazer with horn buttons looks very like any suit jacket. I am wondering wether it is possible to do this, and make it work.
I am wondering wether members here might have suggestions as to style & what cloth to use. I have read here that serge is the traditional thing for blazers.I know that some will say that I should have a separate suit and blazer, but it seems sensible to double up

[Costi]

I think the SB coat of a dark blue gabardine suit, for instance, can double as an odd jacket worn with gray flannels, for instance, even if it is not technically a blazer.

[Concordia]

I think the SB coat of a dark blue gabardine suit, for instance, can double as an odd jacket worn with gray flannels, for instance, even if it is not technically a blazer.

Somewhere there are threads on Manton's "BlazerSuit" notion, which actually post-dates a linen suit I had made on exactly those lines. My Prior Art lawyer is lazy, so nothing's come of that problem. You could probably make it work with tan (warm, sunny weather), medium/charcoal grey flannel, navy linen, and a few other options. I have a 3-button SB jacket (not a suit) made from lightweight herringbone, light navy blue. Flaps, horn buttons. One could order trousers and make it a very useful suit.

For styling, I'd focus on SB notch lapels and consider patch pockets, at least on the sides if not the outside breast pocket. Horn buttons, or maybe same-color MOP for summer jackets. Some fabrics might work also as a DB odd jacket, but that is a more personal choice.

[couch]

Edwin DeBoise of Steed has made a navy suit for Style Forum member Voxsartoria that he calls a "Swiss Army Suit." You can see pictures here.

The idea is that the buttons are removable; you can swap among a gilt set (for blazer wear), a horn set (for suit wear), and a mother-of-pearl set (for odd jacket wear). This might be one way to address your requirements. If gilt is not your thing, you could consider vintage sterling or pewter buttons for the blazer set. If not kept at a high polish, they're less conspicuous but still retain some military / sporting heritage.

[SMCK]

Costi, You do get up early in Bucharest...5.41am. thank you for your advise. I had not thought of gaberdine, and on looking it up here I discovered your first post 2005 and your brilliant dark blue blazer , so lots of help.

Concordia, Thank you for referring me to Mantons idea of the blazersuit, which is exactly what I'm trying to do . Great idea and thank you for remembering it and also for your other styling ideas.

Couch, Well what can I say. thank you for directing me to style forum, which I don't follow but maybe should, as i'd missed that great and exciting post re:Voxsartoria's swiss army suit. What a brilliant idea, can't imagine why I didn't think of that myself. I have several inherited white tropical tuxedos, designed to be washed frequently which have removeable buttons like cufflinks.
Voxsaroria's swiss army suit is as someone on that site said "The concept is genius,by its sheer simplicity-and well executed." It is a great suit and open to many permutations, SB or DB etc.
I think that is now the way I am thinking as it solves most of my problems, so thank you couch for steering me in the right direction.

[Costi]

Costi, You do get up early in Bucharest...5.41am. thank you for your advise.

You are welcome. Hehe - fancy me writing on the LL at 5:41 am 8:41 sounds more like it.
Double breasted is also an option. Take a look at these pictures of plain dark blue DB coats worn as an odd jackets, as well as part of a suit (incidentally at a wedding, which is what you have the suit in mind for).

[SMCK]

I'm a bit late in replying but thank you Costi for those great photos,more or less exactly what I had in mind. I particularly like the look of the middle photo which is I think the look I'm looking for.
I have taken on board most of the advise I have been given
I love Voxsartoria's swiss army suit ( I'm not clever enough to put the link in here) as suggested by Couch.such a clever idea.
Mantons blazersuit is also inspirational.

As to which cloth to use.Micheal Alden has said that serge is the only thing to use, so i'll go with that.
From another thread (to which I have just added) Lesser's 18oz was suggested. I too find this a bit too dark although the cloth is wonderful. I mean to see what their 160z. is like.

If anyone has any suggestions where the best place to get a bit of heavyish navy ( neither too dark or light) serge, I would be grateful.