It depends on if you are able to put reasorces into both or only one. If only one, then wait, if you can use some more resources, you can go for standard Gauss. Priming of Warframe is really minor statwise so it’s mostly cosmetic addition. Also In the next patch there will be added Gauss Deluxe skin.
Wisp Prime should likely come in the span of three weeks from Kullervo update that was teased to release this month (and I wouldn’t be surpriced if she released only after few days from update release)
Stropha offers highest potential damage from all gunblades. Corufell is best AoE but technically speaking is not a standard Gunblade but Heavy Scyphe + Gunblade Hybrid (similar to Wolf Sledge - Hammer + Glaive). Redeemer Prime is honestly pretty close to Stropha in damage, but works more like classic shotgun and has more status. Vastilok is still a strong weapon but lacks compared to other gunblades, but is commonly used as an Armor-Strip Primer instead of Heavy Attack monster thanks to Shattering Impact mod.
And not full of bots like Reddit as a whole.