How would you go about finding a decent implementation partner? Ideally without going thru NS

Google search "NetSuite Alliance Partner" or "NetSuite Solution Provider"

Really if you're in this slack channel, you probably already know some hard questions to ask them to get a sense of their skill level. Pick a small part of what you want them to do and ask them to demonstrate/speak to how they would approach that during the sales process. If you find a consultant you really like, make sure having them doing the actual work is in your contract so they don't pull the old switcheroo (quality can vary widely even within a specific organization).

I can recommend Bryant Park Consulting. Our entire team was thoroughly surprised with how well our implementation went.

Highly recommend Cloud 1001 , Andy Prior is our NetSuite Guru. We are implementing our Manufacturing with that team. We did our Order processing/Sales with Netsuite and could have streamlined SO much if we had Cloud 1001 initially! https://www.gocloud1001.com/

I highly recommend SCS Cloud