Furez FZ102AS Advanced 10AWG 2 Conductor CL3 In-Wall Speaker Cablehttp://www.av-outlet.com/en-us/dept_484.html
This is the speaker cable that i have for my M60's/VP180.
Prior to this, i was using a 4 conductor 12 gauge monster cable that retailed for about 2-300$ for a pair (i bought mine off of ebay for much less used)... I like the Furez more. Rick is right, 14gauge will be just fine... For me i got the 10 gauge, because i wanted to buy something :~).... The other nice thing about the Furez product, is that they post all of the technical specifications of their wires.. Most companies do not do that.. Even though the Furez product is rated for in wall use, it is very flexible due to the manufacture using a silicone insulator instead of a ridged plastic.
On a side note, thee was someone on the axiom forum who recently bought some speaker cables from bluejeanscable, and got them to ultrasonically weld the banana plugs on. I could not find the link to the person on this forum. However, here is a link to the process on bluejeans website.http://www.bluejeanscable.com/articles/ultrasonic-welding.htm
This is one of the only resistance charts that i could find with the per foot/resistance break down, resistance is usually stated in the 1,000' increments.http://www.cirris.com/testing/resistance/wire.html
Here is a larger chart, that shows more sizes, it is in the 1000'/ohm scale, so you will need to do a little math to calculate what each of your runs would be.http://www.powerstream.com/Wire_Size.htm
One other factor in speaker wire "design" ( i use the term design very loosely) is the capacitance of the insulator used, the lower capacitance the better... I am not going to elaborate much more on that...
The real question is.. How much disposable income do you have? if spending 50-100$ on speaker cable is nothing to you, then i say buy some new speaker cable for your new speakers... If you don't have endless pockets right now, then use what you have, as Rick pointed out it will be fine.