I can and have done professional level brush applied finishes, with zero traces of brushmarks.
Those cabs are going to be VERY difficult to do a professional finish in Polyurethene or Varnish. I do not recommend it unless you take the time to learn to do it right. The best brush for those finishes is a high quality badger hair brush, which must be cared for properly between coats.
As long as the environment is relatively dust free it will do. That is not your most important concern, because you will sand between coats and rub out the final coat.
The coats must be even and thin, and corners and edges are HELL, and must be handled delicately. Globs or build-ups in those areas will not fully cure below the surface.
Each coat must be absolutely FULLY cured before sanding between coats, and all brushmarks must be 80% removed before proceeding to the next coat. That could mean 1 to 2 days between coats--5 to 6 coats total. Use a cork sanding block, 220 grit for the first couple of coats, and 320 thereafter. Garnet paper is the most forgiving. Take care not to over sand corners and edges.
There is a technique that you must develop in spreading the finish over a given surface. You have a given amount of time to wet out the surface and spread it out evenly, after which the finish will flatten out, and brush strokes will thereby be minimized. Just one stroke past that point and you are screwed, as the finish will have begun to tack and will not flatten out--the result will be hideous tacky brushmarks.
You initally spread the finish holding the brush at a slightly shallow angle, and the final stokes (longer) are held a bit higher and will help even out and flatten the coat. The last step is refered to as tipping off. You must work fast and accurately.
Sanding: It is critical that you do not sand past the coat you are sanding to the coat below it. Using gloss finish, you can create your own satin finish by using the finest grade of steel wool to rub out the final coat, or work through three grades of Meguiars for a glassy gloss finish. Rubbing out is extremely labor intensive.
If you want a beautiful finish (your interpretation and mine, might differ here) I recommend an oil/varnish finish, that is applied with a rag. I can explain it if you want, and give you the best ingredients and mixtures. It is the easiest of all professional finishes if done correctly, and there is no sanding involved and the finish can end up absolutely suberb if done with care. Its the one I recommend.