$1500 isn't too bad at all, you can do pretty well with that budget. Might I suggest going taking some time to go through the FAQ on this board.
I was wondering, is this just an acapella choir? Will they be using some kind of reinforcement system, like a pa?
I'll start with the mics.
1. Will you need to be very discrete? If not I'll suggest a pair of the ADK A51tl's, they are large diaphragm microphones so they are not very discrete
http://www.cascademedia.net/products.asp?catid=193&prodid=1440They are under $800 for the pair brand new I believe, but they can also be found used here on occasion. These mics offer a very nice sound, I have 10 or so recordings of unamplified baroque recordings from Moke on this board done with these very mics that are very, very nice sounding. These mics have 5 polar patterns which are selectable by a switch on the mic. This makes them very versatile, you will be able to adapt to any room situation. These may be more microphone than what you need or want to take the time to learn how to utilize.
2. If you're looking for something smaller I'll recommend a stereo pair of either Neumann km184's or Microtech Gefell m300's. Both are very fine microphones made by two of the world's finest microphone manufacturer's. Both mics are cardioid pattern mics. Cardoid would probably be your pattern of choice for most of these recordings anyway. The MG's can be had for around $600/pr used while the Neumann's are a bit more (~$850 used I think). I think you would be happy with either pair.
fwiw - the adk's come with shockmounts and windscreens, if you buy the mg's or the neumann's you will need to buy mounts ($60-80/pair used) and windscreens (~$40/pair used)
Next you will need a preamp and an analog to digital converter (again check the faq as alot of the technical terms are explained very well. In your position, with your budget I would suggest the Edirol UA5, specifically one modified by the Oade Brothers see the links on this page
http://www.oade.com/cgi-bin/miva?Merchant2/merchant.mvAll of their modifications are nice but the TMOD is the newest one. Someone more familiar with the subtle sonic characteristics of each mod should be able to really break them down for you. I've heard tapes from all of them and have had the chance to run a TMOD on one occasision and really, for the money, this is the best deal in taping right now. Very portable, easily powered, sounds great. They go for about $530.
Okay, the recorder your friend has is a NOMAD JB3... I think it's your best bet for a recorder. It's small and easily powerable, it will easily connect to your other recording equipment as well as your computer for later. You can find refurbished ones on ebay and used one's show up here occasionaly as well. You will be sending the recorder a digital signal so don't worry about picking up "delicate sounds", that will all be handled by your mics, preamp and analog/digital converter. You're looking at about ~$150 on ebay
Now you need all of the accesories
Mic stand, there are suggested models in the faq I believe but offhand the Bogen 3333 would work well for you. Stands will be ~$100.
You will need a tbar to mount two mics to one stand, I suggest the AKG KM235, should be available at any of our retailers.
You will also need mic cables, someone on this board should be able to build you a nice pair for a good price.
You will need an optical cable to run between the ua5 and the jb3, there are some preferred cable types so I'll wait for the jb3 users to chime in.
This is coming close to your budget but I think you will be quite pleased with the quality of the recordings that this rig can produce.
Good luck, hopefully this gives you a start...