I've got a pair of J Brand too and they really are great! I tried on the skinnies and yes, they were the most flattering skinnies I've ever tried - but didn't get those as already have a pair of skinnies so couldn't justify getting them. I've actually got the 'bell bottom' style and I wear them as my 'smart' going out outfit! They were a silly price but really worth it, I get compliments whenever I wear them.

Ruehl, Lucky Brand, Ezra Fitch, 7 For All Mankind, A&F and Hollister.

The only pair of jeans I've ever worn until they fell to piences (literally) was a pair of A&F Baxter jeans. Everyone who bought them seemed to love them, so I have no idea why they discontinued them.

I've been wearing John Rocha slim bootcut jeans, which seem good for me, 5ft 4 and size 12.

where can you get these jeans from? and how much?

Rhino Horn - I got mine in the states but I think selfridges and harvey nichols stock them. Online stores like my-wardrobe, start-london, browns, matches, and net-a-porter also stock them.
From the US it cost about £80 for my skinnies but over here I think it's about £120. Other styles can go up to £190. Might be able to get it cheaper now the sales are on.

been wearing rock and republic skinny fit for the past 3-4 years (had the crown to the r&r emblem),

thinking about getting a pair of r&r flares soon