This is highly dependent on what you’re looking for. What’s your budget? How realistic do you want it (both how it looks and how it feels)? Do you want a basic packer, an STP, a 3 or 4-in-1? Are you looking for a long term packer/investment or do you want something simple to try out for now? etc.
I would suggest getting a packer that’s only for packing. the 3-in-1 type often have the issue of looking like a boner because they’re more stiff. also get a kinda small size. even if proportionately you think you’d have a 5 inch flaccid penis, it just doesn’t translate the same in silicone. I’d aim for around 3-4 inches. smaller side if you’re shorter, longer if you’re taller. I like Axolom for their realism and price range ($30-70). kinda pricey but cheaper than most other realistic brands.