As much as i too tire of oak. if you are going stain grade with floor and newels?, id say stick with oak.....I agree w klem paint grade id stick with select pine/poplar. Oak makes a very stout and solid newel connection vs chooing a softer wood for a tighter grain and a possible odd look. IMHO.

Carey, it would not be Corian quartz (Zodiaq), it would be Corian solid surface, which is acrylic (?) Joseph, I have been going a little Corian crazy in this house: custom shower receptor, custom vanity tops with a short narrow coved edge that blends with the tile thicknesses, custom toilet paper niche that fits into the tile layout, custom coved shelves that fit exactly into the tile layout, two waste baskets, a "tile" for one specific spot for which no trim tile existed, shelves for the medicine cabinet with holes in them for tooth brushes and razors, and a door to the cat's tunnel complete with "grout lines" and an integrated finger pull, since the cat tunnel in the bathroom also fits into the tile layout. So I am a little obsessive (thinking of a Corian hood for the kitchen) and the fabricators have gamely made everything I have designed and thrown at them. I have an open railing (not code compliant) that is wood (white painted and capped with a piece made of clamshell and pole railing. It needs to redone and fitted with something like mesh in the opening and I will probably make this out of metal for "object integrity" but capping it with Corian and making matching handrails out of corian (Glacier white) and topped with Avonite Fondant (which is the only solid dark brown I can find) would be great and play into my obsessiveness, especially if they could make curved pieces which would probably be out of budget.

Curious... what was the rational to not match new floors to existing tread and handrail stain?If you prefer lighter wood tone (your new floors) you'd need to remove spindles & railing and either sand & refinish (depending on wood species - are treads and new floor same type of wood?) or replace treads to match new flooring... From experience it's a big job! Where did you purchase the flooring - do they sell treads? If not, suggest you speak to a few flooring & stair specialists (not just big box store sales reps no offense meant). When we installed our h/w floors the flooring store's installers were able to sand & match our existing stairs to the new floor...but we had the same wood species (oak) on both... Hope this helps.

Elephant in the Room: "...we are having a friend do the install..." This is fine with flooring (as in hallways, bedrooms, etc) but not a great idea with stairs. As everyone has said (and I will repeat myself) stairs are EXPENSIVE because they deal with CODE. A 'friend' will have to be willing to take ALL LEGAL RESPONSIBILITY should the product that s/he applies cause A. injury or B. fail code. Most friends aren't that excited to be on the hook for 'helping out'. Carpets HIDE the WORST MATERIALS in the building world. By worst I mean CHEAP and POORLY made. That NORMALLY includes OSB. OSB can be the cheapest of the cheap. It is made up of 'chips' of wood glued together with a waxy substance. The very make up of OSB PREVENTS stuff from being GLUED to the surface. Enter: Vinyl stair covering. Vinyl planks/nosing MUST BE GLUED to the stair's substrate. Imagine the substrate as the WORST OSB possible. Stairs need to be strong and meet minimum code. Builders LOVE to use the CHEAPEST MATERIALS on stairs because stairs are INHERENTLY expensive. So....save $300 on the stairs and you have $300 in your pocket (the GC/Builder). So long as stairs are DESIGNED to be carpeted the architect and builder have NO INCENTIVE to make it out of anything other than OSB. I know this is all new to you. So I will spell this out for you: your assumption about plywood (plywood is EXPENSIVE = saved for places where it is NEEDED) is, sadly, a problem. A plywood stair would be AWESOME for your situation. But I would bet dollars to doughnuts you have OSB. And the subfloor UPSTAIRS is probably going to be OSB as well (see discussion about costs of plywood). OSB does VERY WELL under carpet. Carpet can cover hills and valleys and sagging sections of the subfloor (OSB does ALL of those things and MORE). As soon as you want to put down a rigid floor (where carpet used to be) you MUST ASSUME a LOT of patch/repair. Again, this is where the COST of the repair comes in. I have told my clients to BUDGET $2-$4/sf worth of SUBFLOOR REPAIR when removing carpet. Yes. That is the same price as the vinyl planks themselves. The subfloor repair can DOUBLE the cost of your project. Now ask your friend if s/he is GOING to do the 8-16 hours worth of work to PROPERLY prepare the subfloor upstairs. This is when using a friend gets tricky. So long as you are paying them FULL MARKET VALUE for their labour/skills, your friendship will remain solid. If they are doing this for beer and pizza, then things are going to get VERY tense. I know this is new to you, so be PREPARED for MUCH BIGGER project costs than you originally anticipated. If you have to repair the upstairs subfloor AND REBUILD (remove the OSB and then lay down NEW PLYWOOD on) the stairs you are in for a MASSIVE bill. Rebuilding stairs is worth the same price of the vinyl AND the cost of labour to repair the upstairs subfloor. It runs in the THOUSANDS of dollars. Just so you know.