Handlebar height: I think you'll be better off changing the stem instead of the handlebars regarding the height issue. Any 1" quill stem should work (as long as the clamp diameter matches the bars, your current bars should be 25.4mm clamp size), look on ebay for a tall one that also has the forward extension you need. Old SR branded stems are very common on ebay, they're nice looking and would match the bike well, and they usually sell for cheap, some in near NOS condition. If you want a REALLY tall quill stem, go for a Nitto Technomic, available at Harris Cyclery (Sheldon Brown) in a variety of forward extension lengths, and available in both 25.4mm and 26.0mm clamp diameter.

Wider handlebars: Again, ebay might be your best bet. Something like the old Sakae Road Champion bars are very common, would go with the bike well, and sell for cheap. You should be able to find them in a variety of widths. For a new bar, I like Nittos (again, available at Harris Cyclery), they've got them in a variety of widths and I believe some models come in 25.4 and some in 26.0 clamp size.

Brakes: I've got centerpull road brakes on a couple of old bikes, and they're very strong. A couple of things you can do to improve things is to take them apart, clean them up, and lube the pivots with pure silicon spray lube, available at auto parts stores. The bushings in the pivots on this type of brake are often plastic, and they seem to like the pure silicon lube. I would also recommend some Kool Stop salmon brake pads (the best pads currently made, in my opinion), the ones I use on my centerpulls are the cartridge style shoes intended for v-brakes, they're super easy to set up, adjust, etc., because of the spherical washers that come with them. And probably most importantly, change out the brake levers to some aero style levers (Cane Creek SCR-5 are really good, and not too expensive). The difference between aero levers and non-aero levers isn't just looks, the aero levers will actually give more leverage, and therefore better braking performance (some will disagree, but it's a fact that there's a difference in leverage because of the difference in design). Also, the aero levers will have better ergonomics when braking from the hoods, and since it sounds like you'd rather have your hands higher (and out of the drops), that would be an advantage. I'm the same way, I brake from the hoods a lot-