It depends on what part of Manchester you will be in; I take it that it will probably be central Manchester so,
Beer House, 6 Angel Street,
Britons Protection, 50 Great Bridgewater street,
Rain bar, Great Bridgewater street (revamped old building with about 2 beers worth drinking) and quite near it is the quirky Peverill of the Peak (strange place with Deuchars IPA and a few others).
Jolly Angler, behind Piccadilly station (never been myself),
and a little further out from the Rain bar/Peverill place is the Lass 'O Gowrie, down a side street (Charles street) near BBC Manchester. This place had a very good list with 8 - 10 pumps.