I agree with Paul, get the adaptor with neutrik connectors. It looks line the bestpricecables link is neutrik. Cheap XLR connectors will either crumble with regular use or melt when soldered.
Here's a potential issue to be aware of. RCA to XLR adaptors are wired as follows: signal + from the RCA goes to XLR pin 2 and signal - goes to XLR pin 3 and pin 1 (XLR ground). If you connect the amp with the adaptor and get ground loop hum, you may need to lift (disconnect) pin 1 from pin 3 inside the adaptor. Signal - from the RCA should still be connected to pin 3 of the XLR.