Partlist according to www.digikey.com
all prices in us$

ATTENTION!! ALL PRICES ARE PER ONE ORDERED UNIT !!
SOME PARTS HAVE A MINIMUM QTY. TO ORDER, THEREFORE
YOU ARE RESPONSIBLE FOR ORDERING THE RIGHT AMOUNT !!

Note: the parts from digikey seem a little high-priced
to me. At least in germany  most of them are cheaper.
Dont ask me why ........

All these parts are standard parts (except for the a/d converter ic)
Try to get them at local stores, often the have cheap offers.
For example, sometimes you can get a bulk of resistors for a few bucks.
Look yourself......

parts for the interface board :

qty | value                 | order no.        | price | order qty. |
----+-----------------------+------------------+-------+------------+
 8  |     1 kOhm  / 1/4 W   | BC1.00KXCT-ND    |  1,95 |   5 pcs.   |
 2  |    10  Ohm  / 4   W   | P10W3BK-ND       |  -,52 |   1 pcs.   |
 4  |    10 nF              | P10955-ND        |  -,38 |   1 pcs.   |
 1  | 4.700 µF / 35 V 22 mm | P6483-ND         |  3,45 |   1 pcs.   |
 1  | 2.200 µF / 35 V 20 mm | P6481-ND         |  3,22 |   1 pcs.   |
 1  | rectifier C5000/3300  | GBJ1002DI-ND     |  2,00 |   1 pcs.   |
 1  | 78S05                 | NJM7805FA-ND     |  0,63 |   1 pcs.   |
 1  | 78S12                 | NJM7812FA-ND     |  0,63 |   1 pcs.   |
 1  | 74LS08N               | 296-1633-5-ND    |  -,48 |   1 pcs.   |
 1  | RJ 11 4p/4c           | A9041-ND         |  0,80 |   1 pcs.   |
    *(RJ 11 6p/4c           | A9042-ND         |  0,67 |   1 pcs.   |*)
 1  | db 25 male / 90 degree| A23271           |  5,22 |   1 pcs.   |
 1  | 16-pole ic socket     | A24809-ND        |  -,23 |   1 pcs.   |
 1  | 14-pole ic socket     | ED2101-ND        |  1,68 |   1 pcs.   |
 1  | 2x8 pole pinhead,     | 929838-04-36-ND  |  2,37 |   1 pcs.   | NOTE ! HAS 72 PINS ! CUT IN PIECES TO FIT !
    | 90 degree             |                  |       |            |
 2  | heatsinks,            | 3451030-ND       |  2,31 |   1 pcs    |
    | SK104 50mm long       |                  |       |            |
----+-----------------------+------------------+-------+------------+


parts for one ad board :

qty | value                 | order no.        | price | order qty. |
----+-----------------------+------------------+-------+------------+
 1  | TLC 1543 CN from      | 296-2885-5-ND    |  3,87 |   1 pcs.   |
    | TEXAS INSTRUMENTS     |                  |       |            |
 1  | 74LS08                | 296-1633-5-ND    |  -,48 |   1 pcs.   |
 1  | 74LS05                | 296-1631-5-ND    |  -,48 |   1 pcs.   |
12  |   1 kOhm / 1/4 W      | BC1.00KXCT-ND    |  1,95 |   5 pcs.   |
 2  | 100  Ohm resistors    | BC100KXCT-ND     |  1,95 |   5 pcs.   |
 1  | 20-pole ic socket     | ED2104-ND        |  1,95 |   1 pcs.   |
 1  | 16-pole ic socket     | A24809-ND        |  -,23 |   1 pcs.   |
 2  | 14-pole ic sockets    | ED2101-ND        |  1,68 |   1 pcs.   |
 2  | 2x8 pinhead,          | 929838-04-36-ND  |  2,37 |   1 pcs.   | NOTE ! HAS 72 PINS ! CUT IN PIECES TO FIT !
    | 90 degrees            |                  |       |            |
11  | RJ 11 4p/4c           | A9041-ND         |  -,80 |   1 pcs.   |
    *(RJ 11 6p/4c           | A9042-ND         |  0,67 |   1 pcs.   |*)
----+-----------------------+------------------+-------+------------+


parts for board-interconnection
===============================
(as needed)

 DIL Cable connector    CDP16T-ND  1,45 / 1 pcs.
 ribbon cable connector CSC16T-ND  1,55 / 1 pcs.

get an old flat ribbon cable from a computer or similar.
take 16 poles and cut them from the rest of the cable.
use this for crimping with the connectors. or buy some new...