Uhhhmmm. So, we'll call light - medium winds under 18 Kts. That includes a typical sea breeze which in DC may not really exist. Heavy winds I would call 18+. And going dead downwind in 18 kts. will only be 13 kts. felt on the boat. I think the cheaper one would be OK. Sailing DDW in 18+ Kts. might be a little sporty with regard to an accidental jibe. Are you prepared to rig a preventer? '
I'm missing the point about measuring your Genoa to a 10' foot with a tight furl. But if that's how you manage your sailplane going down wind the pole is only going to be about 10' long and will be essentially two tubes together. It "Should be" strong enough. Your results may vary. And if it breaks you've saved enough money for a new one.
For awhile I used a boat pole for a wicker pole on my H356. The pole didn't fail but since I attached it to the strut bolt, the bolt bent.
If you only going to use the pole at that 10' length you may use a wooden pole. You may find on in a marine scrap yard or even be able to make one out of spruce. It wouldn't cost $450.