It depends on how you use the room and which room the door leads into, I think. If you use this as the main sitting room/lounge I would be tempted to just put vertical panels to close it up, so you can store whatever under the stairs, and put the TV above the fireplace instead. If you do bifold doors I think you can get away with mounting the TV on one of the panels and the door can open in a way that won't bother the Tv. I have something similar in my new build, but the developers did not use the full length under the stairs so the storage 'room' is rather small. I use the remaining of the space outside to put an American fridge freezer (under stairs space is inside my kitchen diner.)

Hi Catherine these were bespoke made by my Carpenter. It took about 3 days, a week if you count his off site work. You can message me for details if you'd like. Not as pricey as the quote on here.

Hi Adam, we also looked at both sliding doors and slide and turn for our opening and were shocked at the price of the slide and turns. One thing that a few designers and window providers said to us was that essentially slide and turn doors (or bifold doors) look better when they are open, and sliding doors look better when they are closed (as they tend to have fewer panels and so less view is blocked by pane). As we are based in London, where for most of the year the doors will be closed, we were advised by everyone to go with sliding doors. (NB our opening is wider, so it was a difference between 3 sliding door panels or 6/7 slide and turn panels).

You're really looking at either a hi end kitchen company who supply a more traditional style kitchen ie inframe, or as @Daisy England says, go to an independent, but as you're planning on having this sitting on your worktop, depending on the design of the rest of the kitchen ie if you have towers, the counter level bi fold doors would be to a special size (as most tall doors are designed for tower use). The easiest way to do this would be to have an extra wide larder (800 or 900), fit an internal drawer unit at the bottom, then a piece of worktop, have power points inside and 2 or 3 shelves above. Depending on where the doors come from it may 2x 1965 doors or 2x 1245 doors at the top and 2x 715 doors at the bottom, all standard stuff. Bearing in mind the appliances your trying to hide would be too big to fit inside a 'standard' 300 deep dresser type unit, the counter top option might not be the most suitable. But for a budget of 20K, i could design and supply a larger than average kitchen that has some bespoke made to measure doors and specially designed rigid cabinets and all to a high spec.