MDF is too soft to use for hanging a door. It would be fine for just lining the doorway---no door. If you need a door in the opening, rip plywood---you can get hardwood ply at lumber yards-----for the 11.5" width. You could install the trim flush with the inside of the ply to cover the plys.

Gemcap and Terri_pacnw, the system in the drawers in just called drawer peg organizer. It does have a notch to remove it. Mine is the Rev-a-Shelf brand. It looks nice and keeps everything organized but I found out after the fact that it really isn't necessary if you have good soft close drawers. There have been a number of threads on these organizers which you should be able to find with a google search and the terms gardenweb + dish drawer organizers or peg dividers. Most GWers agree that you can stack dishes in drawers without the pegs and that the pegs actually waste some drawer space. Some posters did say they used some type of liners like cushy cupboards in their pegless drawers. Nothing really moves when I close my soft close drawers. So while the pegs look nice, I say save the cost. I am sure you can find something else to spend that extra money on.

Sorry for the unintentional mystery everyone! I have been clearing my counters and taking pictures to try to be helpful on several threads on GW and got tired of it, so I figured what the heck, I'm actually living here, right! Anyway, my marble island is in it's 12 month of use and was etched practically on day one, and weekly since then. After my daughter shook the Tropicana OJ jug (the one that USED to be 64 oz that they redesigned with a fancy flip lid that isn't easy for kids to get to fully close) and OJ flew all over the island, I gave up with babying and use it almost without care. Cheeseburgers were on the menu last night. Anyway, you who guessed cheese are right; it is grated cheddar. The plate is one of Villeroy & Boch "Design Naif" patter. There actually isn't anything on it but the painted scene. This pattern is actually a quaint set of six different scenes on each plate. I'll show you a pic with all 6 scenes to satisfy any curiosity. On the black meat tray is some unused raw burger meat that I ended up making my dogs do tricks for after dinner. There are a couple knives and, yes, a tape measure since I was getting info to answer someone's question about the dimensions of something on my island. To the right you see some thin slices of bread that I threw out. I used Zomick's challah rolls for our burger buns and they are a bit high. To make them easier for my son to eat a burger in, and to make them slightly less carb-ful for myself and husband, I sliced out the middle. To the right of that is what's left of a large, delicious tomoato that I made a sliced tom/mozz/basil salad with. I know, horrifying that a cut tomato would be on my marble. However, we're planning to have the island honed this summer due to all the etching it has received, so it sort of doesn't matter too much. Sorry for the hijacking this thread!!!! OP - a couple of things. First, RH often has sales. If you can wait it will be well worth it! Second, buy MANY more pieces of hardware than you think you will need. Lucky for me that there is a RH store near me bc I kept having to go back, at least 5 times, to get more. I counted with my installer, three times, before shopping and bought one extra of each. Some went missing, some were defective, a few were the wrong finish and labled wrong - stuff happens. The good thing about RH is that they have a wonderful return policy. The bad thing about possibly less expensive other retailers, especially online retailers, is that they may only give store credit or may charge a restocking fee, plus online you have to pay shipping to make a return. Also, buy a sample of whatever you are leaning toward before committing fully. Sometimes what you see and what you hold and feel are two different things. Last, yes RH was a bit expensive, although I saw much more expensive as well. But, they had the variety of sizes I wanted and they feel wonderful and are very well made. FWIW, I found some bin pulls on ebay that worked fine for a mudroom bench we made. Up close they are relatively a bit cheap looking, but they are functional and look fine from a distance. Best of luck to you!!! Feel free to ask any questions if I can be helpful! Time for me to payback GW for all the amazing help I found here!

Any door manufacturer should offer some of their door styles in 12". Not all doors will be available in that size. Is it a real door or a cabinet door? Jeldwen and other interior door manufacturers would be a place to start. These will be custom doors. Good luck!