Pickle, passivate and Electro-polish.

55 gallon drum of Elbow Grease

Suntec makes a couple belt sander/polishers that will do the job run about $800.00 for the heavy duty model ( will do up to 12" pipe) Only finish I will do on SS. is #4 satin.( big enough P.I.T.A).

First thing to do is start out with #2 finish, stainless.  The next thing is to have the proper grinders (oscillating type), grinding disks, rouge sticks and cloth wheels.  The second thing you need to know how to apply the correct amount of pressure and grinder speed, which, by the way, requires a lot of skill.

You need to start coarse enough to remove stock, about 60 grit flap wheel, then progress finer. I use 120 grit next, then go to coarse Scotchbrite type wheels, the medium & fine. After that You can go to a sisal buffing wheel and coarse black compound followed bu a close sewn muslin wheel and finer white compound. If this isn't bright enough use a loose sewn wheel and whatever finer compound You have.

The big point is to remove ALL of the scratches from the last [coarser] grade of abrasive before You go to the next [finer] one.

If You are doing flat work, You need to start with a woodworking style belt sander to get everything flat, and then be extremely carefull with the scotchbrite wheels so You don't make "waves" in the surface. If You can get scotchbrite belts, use them. Then procede as above, but use a felt disc on an angle grinder in place of the sisal & muslin wheels. Flat work is a *****, because when You approach the look of a mirror, it will look like hell if it isn't extremely flat.

Walter makes a great line of products for this, but they are not cheap. You would be best looking at the catalog.

http://www.welderssupply.com/product_information.asp?product_id=5298
http://www.walter.com/Walter/en-us/abrasives/finishing/variable-speed-grinder-steel-stainless-aluminum/felt-cup-disc

I wouldn't think glass bead would work that great for hand railing due to the coarse profile left on the stainless. The coarse profile will gather dirt and other contaminants on the hand rail and make it harder to clean. I would think that a round / pearl ceramic bead would be a better option due to the smooth and uniform profile it leaves. Using Avesta Blue prior to blasting would help to ensure a uniform appearance over the welded joints.

If you used prepolished / prefinished tubing as Eric suggested you could passivate in the areas where it was welded and only have to polish those areas.