This is going to be a nice endeavor. The difference of having good equipment will be more noticeable in a good hall than in the living room. It's nice that you have a recording engineer to help you to record, edit, and master the final product. Indeed, a small recorder will not give the signal to noise ratio, fidelity, nor the dynamic range that can be achieved in a good and quiet hall armed with a nice Steinway D. Please, make sure the hall is quiet!
David is right, don't concern yourself with multiple mics, unless your hall is exceptional then you'll mic 2 distant pairs to capture the ambience and mix that into the direct tracks. But, this is easier said than done. Stick with an A-B spaced pair of small condensor mics spaced 15-18 inches apart, 6-9ft high, 5-9ft from the curve of the piano pointed down along the parallel axis of the lid. You will have to experiment with the distances to determine the amount of "air" you want from the room and the amount of direct sound from the instrument. It will also depend on the room characteristics like size, brightness.
I won't go into too much detail here, but allow me to say that mic selection is important. You need a mic preamp and mics that are tonally neutral, have fast transient response, and have a flat EQ response. The final sound depends on the pianist, piano, room, and then the mics (in that order). Repertoire and genre of music is an important consideration too. In my opinion, Rode NT5 mics you mentioned are too bright. Most Neumann mics are too bright too for classical piano. The U87 is a fantastic mic, even great for jazz up close, but it's mainly a world-class vocal mic - a bit colored, and not the first choice for classical piano with a broad peak at ~8kHz. However, if you're really intent on the Neumann, and if your engineer has a large collection of mics from his studio, then the Neumann M50, TLM170, U89i, M149 (in that order) will give you a stellar and majestic sound. However, a matched pair of these mics are in the $6,000 to $12,000 range. Hey, if it's a large studio with deep pockets, access to mics are easy.
Here is a link to my first thread here on PS as it has a lot of useful info, links, and charts. It gives information regarding mics, preamps, recorders, etc. suitable for classical piano recording:viewtopic.php?f=8&t=2844
My recommendation is to go with a pair of small condensor mics: Schoeps MK2, DPA, or Sennheiser MKH8020 omnis. Personally, I find the the Senn MKH8020 to be an excellent match for capturing the bronzed sound of the Steinway D for classical piano. With response down to 10 Hz, it also excels as an organ mic. Here is a photo of the Sennheiser MKH8020 in action. You can feed it into a Sound Design 722 directly without a preamp, or use an external preamp (preferred) and use a Tascam DV-RA1000HD, Korg MS-2000, or another 24bit/192kHz recorder where the internal A/D conversion is more than adequate.