Is the adjustable comb and LOP important to you? If so get the B&C since it has all those options already. If you have them added to the Manners it'll greatly increase the cost of that stock.
My experience with B&C stocks is somewhat limited as I've only used the 2950 Mountain Rifle ADL stock. for a model 700 rifle. That stock took a lot of fitting to get my barreled action in it correctly. The other B&C stock I've owned came on a M70 Extreme Weather rifle which I found too thick in my hands to handle well, I replaced that stock with a McMillan which fit me better.
On the 2950 stock I thought my screw spacing was off, it turned out my barrel inlet wasn't deep enough. It had the front action screw hole at an angle and not square, so the front action screw wouldn't ever catch a thread. B&C did state that it would take fitting by a qualified smith to work, so I wasn't surprised when I had problems getting my barreled action to fit. I don't know how well the initial fit of the A5 stock you're looking at will be.
I have no experience with Manners, but as stated they are way behind from what I've read on several forums. However, I'd call Manners directly and not go through Stocky's. I've heard Manners will ship you a stock to handle that isn't inlet for any action, for a refundable deposit. That is pretty sweet deal as you get to see how the stock feels to you before you buy.
Have you looked at McMillan? I've found there stock to be pretty much a drop in fit and have been very pleased with everyone I own. I've never purchased a new stock but all 2nd hand, for a substantial savings. However,
McMillan has an A5 stock available right now in a painted black or 50% Olive, 25% Black, 25% Tan marble for only $100 more than the B&C stock you are looking at.