Those are both great choices, but the winner for me would be the Glock 34 by far. First, I don't like external safeties for defensive weapons, but that's a personal preference. Second, I prefer a constant trigger pull, rather than DA/SA. The trigger is better on the Glock. The G34 would be hard to beat for a HD & competition weapon.
Accessories are readily available for both of those weapons.
Having said that, there are many other great choices as well. But, I gather from your post that you've at least held and possibly shot these firearms (?), so if they both feel good to you it's ultimately up to you. Have you held/shot any other options? XD, M&P, CZ, Sig, etc?