What goes with a really nice tuxedo style jacket?

[Carmenere]

My dsis has given me a really lovely tuxedo style black jacket, it fits me really well and cost around £300. Unfortunately she didn't have trousers to fit me to go with it (she has a clothing line btw). So it is my birthday on Friday and dp is bringing me to a really nice but casual restaurant and I would like to wear it and am going into town today to find something to wear with it but what?

A black t-shirt and smart jeans? A skirt? A shirt? Help please? Am having a crisis of confidence!

I'm a size 16/18 and 5'10"

sounds lovely, and ideally matching trousers would be best, but I don't think you'll be able to get that, and it's going to be impossible to find black trousers in exactly the same tone of black and material....
so, I would go for something completely different
what?
not sure yet
will have a think
Is the jacket quite long?
how fitted is it?

How about these?

possibly
but you need a really cool t-shirt to go with a combination like that
something in that vein www.sugarbullets.com/Woman/amplified/

Those t-shirts are great BUT would I look, as my mum used to say, 'mutton dressed as lamb' considering that it is my 37th birthday and I am not quite as fab as I used to be
Would a plain black t-shirt do?

I'm 37, that's not old!!!!!
plain back too mumsy

how about something like that www.coast-stores.com/fcp/product/-/ALLTops/Gabriella-Pleated-Scoop-Neck-Top/2374845410
love the colour

Oh that is nice. How about black jeans and a coloured top?

okay, am going to butt in now - as someone who has worked the tuxedo jacket look many times!
That top from Coast is lovely but won't work well under the jacket - you need something more streamlined, since the jacket is structured. You also can't possibly have that dangly bit hanging off it.
So... I reckon go for a camisole top - the more vintagey the better - provides a lovely, feminine, sexy counterbalance to the slightly masculine edge of the tux jacket. Go for a champagne or pink colour if you want to be subtle, or something like aqua if you don't. Something along these lines
Then wear it with black or white jeans and a pair of heels and either some hoop earrings or a necklace - not both together.
You will look HOT!!

Ok so I got these and a brown sleeveless draped top.

And I got a gorgeous pair of burgundy suede peep toe high heels in TK Maxx for just £8.

Normally I wouldn't wear anything with diamonte on but actually the jeans fit really well.