impedance matching and interconnect capacitance

I am considering moving my rack from between my speakers. The move would require me to have 25ft long interconnects single ended between my pre and my mono block power amps.

According to the specs of my amps, the impedance matching should not be an issue 260ohm output from my ARC SP-16, into a 100K ohm load at the input of the Quicksilver Mono blocks.

The manual for the SP-16 states that a maximum output capacitance is 1000pf.

I plan on using Mogami 2549 as the interconnect with a total capacitance of 87pf/m or 661pf total for 25 ft [7.6m] (not including connectors). This would leave me 340pf shy of the limit. Is this enough or are there other sources of capacitance to consider?
That should be OK. FWIW you would do a lot better running balanced as opposed to single ended for lengths like this- you will get far less coloration from the cable.
Ralph, thanks. I am aware that balanced would be preferable, in fact I initially thought I would have no choice. But switching from SE to balanced would require me to change both my power amps and pre. A big change I am not ready for at this point.
Nick, using Jensen transformers on the output of your pre and input of your amps would let you utilize balanced cables without replacing your electronics.
With the output impedance of your ARC SP-16 at 260ohm and your capacitance of the cable at 661pf will make a HF filter at -3db at 926khz, no problem at all.
And the spec for 1000pf max load capacitance of your ARC is the max it can take for it may start to ring on "square wave test" as with 1000pf the -3db is at 612khz, still not effecting the audio band at all.
So it will just come down to if there is any noise with this length of single ended interconnect, or the colourations it may give.

Cheers George
Great cable in one of listening rooms we have a 5.2 system done completely in Mogami XLRs and speaker wire.
We just changed the XLR runs but they were 20 ft with a pair of Meitner MTR 101s. The rear channels are with Mogami and are 35 ft runs that sound better than the Straight Wire 10 ft runs.