selling dealer said those will work fineHe is wrong. These amps need a balanced signal that you will not get through an adaptor.
In addition to the Jensen transformers that Al mentions above, and that I used, K&K sells a Lundahl version that plugs directly into the XLR input on the amp. Both should work fine, but the Lundahl version would negate the need for a second set of very short XLR ICs. If you do get the Jensen version, get two of the mono style (PI-RX) so you can sit one next to each amp. You will then need two quite short XLR to XLR ICs to run from the transformers to your amps. I have a pair if you are interested. Otherwise, try the Lundahl version that doesn't need the second IC.
Also, there are impedance matching issues with the transformers. The issue benefits from the Clayton's high'ish 100K ohm input impedance but you should still try to use a preamp that has a low output impedance. I was mostly using a Tom Evans preamp with an output impedance of less than 100 ohms but I did also use a Lamm LL2 and it sounded very good as well. If specific questions about matching with your gear, talk to the folks at Jensen or K&K.