No matter what, your gi will shrink. Even if it says "pre-shrunk".
No need to get a brand name gi as a beginner, unless you really want to or it's easier to get in your area. Get a double-weave.
Size-wise you really have to go with the suggestion of the supplier. Hatashita are reputable, as are Kodokangear (I've met the owner Vin during his visit to Australia he's a nice, honest and helpful bloke).
Another good place is Fushida with Christo's own Fushida suits. What I like about him is he'll let you pick different pants sizes to gi tops and he'll even pick a slightly more slim or baggy fit off the shelf to suit your build (which he gets from detailed measurements you provide). I own 2 of his suits which I got about 2 years or more ago and they are holding up really well.
Fushida World Martial Arts Supplies - Vancouver BC Canada - Judo Uniforms - Judogi - Jiu-jitsu Gis Uniforms - Accessories for Martial Arts
Do NOT ... repeat NOT buy from judogis.com. They are bad, unreliable etc (not from personal experience but from MULTIPLE bad experiences from various people at JudoForum over the years)