Like you said, I need to shoot the HK's before deciding anything. I just retired from my LE job here after 38 years, and had carried a DAK P229 for the last two years. They gave me my pistol when I retired.
I tried putting a slip-on rubber "boot" on the grip, but it shifted around too much. I put skateboard tape on the 229's front-strap, which helped a lot. Then I had a guy at a local gun shop do a really masterful job of stippling the 229's backstrap and thumb-rest area, which helped even more with it being a tad too small. It handles a LOT better now...but I wondered about the HK's.
Since the P2000 has inter-changeable grip-straps, it seems like that'd be the way for me to go with me having really large hands. I picked up a P2000 a couple years ago at a gun shop, and when I extended my arm, the front sight came up slightly low. The Sig 229, on the other hand, comes up naturally with the sights perfectly aligned. But maybe the P2000 I handled had the wrong backstrap insert for my hand.
I'm glad you have a P229 also. It was a help to me. Is one more accurate than the other for you?