Help me with shapewear!

[pollysproggle]

Looking for recommendations for shape wear- there are so many brands and they vary so much in price I'm confused.
Also the sizing confuses me!

I don't wear shape wear ordinarily, I'm reasonably slim size 12 and 5ft 10". I want to wear it under my wedding dress which is a very light material and maxi with a v neck plunge.
I've had two children so I want to smooth out the wobbly bits if at all possible! Must be shorts/long leg type as bum has seen better days believe me.

I remember having a pair of shape wear shorts years ago (the only time I tried them and probably a cheap pair). The leg bits rolled up and were visible even in jeans!
I may be asking for a miracle here but I don't want anyone to know I'm wearing them with a tell tale line across my thigh.

Any tried and trusted brands? I'm happy to pay out as it's a special occasion. Also with the sizing do you go for the size you are or bigger/smaller?

Thanks!

I like the M&S 'wear your own bra' slips as they really smooth you out, but are easy to go to the loo in and don't cause lumps

Thanks Dibbler,
I have seen those but worried they would ride up?
What is the sizing like for m&s?

I never have problems with them riding up as they have a sticky bit round the bottom. They run true to size

Thanks I'll try them.