Which buffer to choose

That little board indeed is a little simple.
It also misses the electrolytics (47µF) from the schematic.
The values on the board also don´t match the schematic.
The input resistor for example seems to be 56Ohm on the board instead of 100Ohm.

If you go that route be prepared to measure all resistors, exchange a couple
and somehow install a coupling capacitor for safety (or be absolutely sure that you don´t need it). Plus finally measure the output offset.
R4=47k should be a wire/0R or <10Ohm in order to make it work as a buffer.
The output resistor can be made smaller but 47Ohm (if populated) should still be OK with your Pascal modules.
And of course you´ll need a regulated supply of min. +-5V better +-10V...+-18V
and an opamp as it seems that it is not supplied with the board.
There are many board on eehbay alone but lots of them have questionable coupling capacitors that should be exchanged. Most do not provide a schematic too.

If you don´t have that kind of supply it will probably be much easier to find a board with regulators on-board or buy an extra PSU.

There´s also discrete buffers but as always, the performance should be measured upfront, even if schematics are provided and all looks kinda nice:
Diamond buffer board stereo broadband strong driving capability assembled ! | eBay