Substitutes:

• Tennessee Whiskey: If you don't have Tennessee whiskey, try using bourbon for a similar I've also used Canadian whisky in a pinch, which adds a smooth touch.
• Rye Whiskey: You can substitute rye whiskey with Scotch for a smokier flavor or use Irish whiskey for a lighter taste.
• Pamplemousse Liqueur: If unavailable, use triple sec with a splash of grapefruit juice to mimic the citrus notes.
• Bittersweet Orange-Red Aperitivo: If unavailable try with a touch of triple sec and orange bitters.

Making a Pitcher of Sunset Strip:

• Scale: To make a pitcher that serves 8, multiply all the ingredients by 8. That would be 8 oz each of Tennessee whiskey, rye whiskey, and 4 oz each of Pamplemousse liqueur and bittersweet orange-red aperitivo.
• Mix: In a large pitcher, combine the whiskeys, Pamplemousse liqueur, and aperitivo with ice. Stir well.
• Serve: Strain the mixture into chilled coupe glasses, garnish with a grapefruit twist, and serve immediately.

Making it Non-Alcoholic:

• Whiskey Substitute: Use non-alcoholic whiskey alternatives; these are available and provide similar flavors without alcohol.
• Pamplemousse Liqueur Substitute: Create a simple syrup infused with grapefruit zest for that citrusy touch.
• Aperitivo Substitute: Opt for a non-alcoholic aperitif or make an orange-infused simple syrup with a hint of bitterness from gentian roots. 
• Proceed As Usual: Use these non-alcoholic substitutes instead of the regular ingredients, follow the original steps, and enjoy a non-alcoholic version.