In our family room there is an exposed LVL 18.5' long that I would like to apply veneer to. It looks like paper backed will give the best results because the LVLs aren't perfectly flat, but I'm curious about what species might work best for us? There are a LOT of choices out there but I was thinking maybe walnut or something stained dark for contrast with the flooring? Is it possible to find anything that's bookmatched lengthwise or do I need to look for something that doesn't have a strong grain to avoid an obvious seam in the middle?

This is the beam in question.

most any veneer you buy will be sequenced, so you could bookmatch lengthwise no problem. The challenge you will have is how flat your surface is. Veneers are typically 1/42" thick, so any bumps/lines/unevenness will show through very well in the veneer. I would consider putt 1/2" or 1/4" ply as a backer up to flatten it out.

The other option is to get thicker veneer. Not a lot of places stock or carry them, but Certainlywood.com has veneers that are 1/10" thick. They are my go-to for veneers. I would give them a call and tell them your project and they can give you input. I've used them before and told them what I needed and size and they checked their inventory and came back with suggestions. Very helpful.

Very cool - I had no idea they were sequenced. That opens up a few more possibilities and I'll have to call that place up and see what our options are here.

I planned on doing a decent amount of prep work on the LVLs before putting up veneer. They're covered in resin on the long sides and a palm sander with coarse grit sandpaper seems to do a pretty good job of removing bumps. Nail holes have been easy enough to fill in and aside from that there really aren't any major imperfections or chunks missing.

The wife wants me to hurry up with it so I'll probably get an order in late today or tomorrow. Do you know about what their turnaround time is like? I know Thanksgiving is upon us but she'd be thrilled if I could be done by Christmas.

They are pretty quick, 2-3 business days to ship. If you browse their inventory you will see pictures of each stack of veneer. They show a single picture of the stack, and each piece in the stack is cut from the same piece of wood in sequence. Veneers are very particular, and the pictures of the wood you see will be the exact board you get your pieces from.

When I do projects and model them in 3d, I get the pictures or the veneer I am going to use and insert the pictures as the graphics in my model so I can see exactly how the piece will look with the veneer

I wound up ordering through Oakwood Veneer. I called Certainly Wood and because of the application, a paper backed veneer would be the best choice and that's something they don't sell. I was told that with the 22.2 mil backing I can install it with normal contact cement. Sometime this week the order should get here and then I can install it with enough to spare for me to experiment with different finish options.